From 09bc74af86c5568dfd960a8f489a5dda026fafd8 Mon Sep 17 00:00:00 2001
From: m7pr <m7pr@users.noreply.github.com>
Date: Fri, 22 Dec 2023 13:24:18 +0000
Subject: [PATCH] deploy: 99336f8678cafb2c8608862ed2c5cfe1cbd9fe4d

---
 main/coverage-report/index.html | 5589 ++++++++++++++++---------------
 1 file changed, 2819 insertions(+), 2770 deletions(-)

diff --git a/main/coverage-report/index.html b/main/coverage-report/index.html
index f9bf986da..05ded9ca3 100644
--- a/main/coverage-report/index.html
+++ b/main/coverage-report/index.html
@@ -94,7 +94,7 @@
   font-size: 11px;
 }</style>
   <div class="col-md-8 col-md-offset-2">
-    <h2>teal.data coverage - 78.35%</h2>
+    <h2>teal.data coverage - 78.51%</h2>
     <div class="tabbable">
       <ul class="nav nav-tabs" data-tabsetid="covr">
         <li class="active">
@@ -106,8 +106,8 @@ <h2>teal.data coverage - 78.35%</h2>
       </ul>
       <div class="tab-content" data-tabsetid="covr">
         <div class="tab-pane active" title="Files" data-value="Files" id="tab-covr-1">
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+          <div class="datatables html-widget html-fill-item" id="htmlwidget-3c57ab4a53cf246ec816" style="width:100%;height:500px;"></div>
+          <script type="application/json" data-for="htmlwidget-3c57ab4a53cf246ec816">{"x":{"filter":"none","vertical":false,"fillContainer":false,"data":[["<a href=\"#\">R/deprecated.R<\/a>","<a href=\"#\">R/formatters_var_labels.R<\/a>","<a href=\"#\">R/default_cdisc_join_keys.R<\/a>","<a href=\"#\">R/zzz.R<\/a>","<a href=\"#\">R/dummy_function.R<\/a>","<a href=\"#\">R/teal_data-show.R<\/a>","<a href=\"#\">R/cdisc_data.R<\/a>","<a href=\"#\">R/teal_data.R<\/a>","<a href=\"#\">R/verify.R<\/a>","<a href=\"#\">R/teal_data-get_code.R<\/a>","<a href=\"#\">R/join_keys-utils.R<\/a>","<a href=\"#\">R/teal_data-class.R<\/a>","<a href=\"#\">R/utils-get_code_dependency.R<\/a>","<a href=\"#\">R/join_keys-extract.R<\/a>","<a href=\"#\">R/join_key.R<\/a>","<a href=\"#\">R/join_keys-print.R<\/a>","<a href=\"#\">R/topological_sort.R<\/a>","<a href=\"#\">R/join_keys-parents.R<\/a>","<a href=\"#\">R/testhat-helpers.R<\/a>","<a href=\"#\">R/join_keys.R<\/a>","<a href=\"#\">R/join_keys-names.R<\/a>","<a href=\"#\">R/utils.R<\/a>","<a href=\"#\">R/teal_data-datanames.R<\/a>","<a href=\"#\">R/join_keys-c.R<\/a>"],[351,150,36,20,25,19,38,58,117,62,144,97,306,281,92,61,69,141,55,160,31,45,50,47],[65,40,11,8,5,4,1,18,37,13,67,24,90,113,33,31,28,28,22,20,15,10,10,10],[0,0,0,0,0,0,0,11,28,12,64,23,89,113,33,31,28,28,22,20,15,10,10,10],[65,40,11,8,5,4,1,7,9,1,3,1,1,0,0,0,0,0,0,0,0,0,0,0],["0","0","0","0","0","0","0","46","1","33","59","65","158","120","817","13","274","218","36","256","3","7","26","191"],["0.00%","0.00%","0.00%","0.00%","0.00%","0.00%","0.00%","61.11%","75.68%","92.31%","95.52%","95.83%","98.89%","100.00%","100.00%","100.00%","100.00%","100.00%","100.00%","100.00%","100.00%","100.00%","100.00%","100.00%"]],"container":"<table class=\"row-border\">\n  <thead>\n    <tr>\n      <th>File<\/th>\n      <th>Lines<\/th>\n      <th>Relevant<\/th>\n      <th>Covered<\/th>\n      <th>Missed<\/th>\n      <th>Hits / Line<\/th>\n      <th>Coverage<\/th>\n    <\/tr>\n  <\/thead>\n<\/table>","options":{"searching":false,"dom":"t","paging":false,"columnDefs":[{"targets":6,"createdCell":"function(td, cellData, rowData, row, col) {\n  var percent = cellData.replace(\"%\", \"\");\n  if (percent > 90) {\n    var grad = \"linear-gradient(90deg, #edfde7 \" + cellData + \", white \" + cellData + \")\";\n  } else if (percent > 75) {\n    var grad = \"linear-gradient(90deg, #f9ffe5 \" + cellData + \", white \" + cellData + \")\";\n  } else {\n    var grad = \"linear-gradient(90deg, #fcece9 \" + cellData + \", white \" + cellData + \")\";\n  }\n  $(td).css(\"background\", grad);\n}\n"},{"className":"dt-right","targets":[1,2,3,4]},{"name":"File","targets":0},{"name":"Lines","targets":1},{"name":"Relevant","targets":2},{"name":"Covered","targets":3},{"name":"Missed","targets":4},{"name":"Hits / Line","targets":5},{"name":"Coverage","targets":6}],"order":[],"autoWidth":false,"orderClasses":false},"callback":"function(table) {\ntable.on('click.dt', 'a', function() {\n  files = $('div#files div');\n  files.not('div.hidden').addClass('hidden');\n  id = $(this).text();\n  files.filter('div[id=\\'' + id + '\\']').removeClass('hidden');\n  $('ul.nav a[data-value=Source]').text(id).tab('show');\n});\n}"},"evals":["options.columnDefs.0.createdCell","callback"],"jsHooks":[]}</script>
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           <div id="files">
@@ -600,105 +600,105 @@ <h2>teal.data coverage - 78.35%</h2>
                 </tbody>
               </table>
             </div>
-            <div id="R/join_keys-extract.R" class="hidden">
+            <div id="R/utils-get_code_dependency.R" class="hidden">
               <table class="table-condensed">
                 <tbody>
                   <tr class="never">
                     <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r"># get_code_dependency ----</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 2</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' Get Code Dependency of an Object</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">4</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @section Functions:</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `x[datanames]`: Returns a subset of the `join_keys` object for</pre>
+                      <pre class="language-r">#' Extract subset of code required to reproduce specific object(s), including code producing side-effects.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' given `datanames`, including parent `datanames` and symmetric mirror keys between</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' `datanames` in the result.</pre>
+                      <pre class="language-r">#' Given a character vector with code, this function will extract the part of the code responsible for creating</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `x[i, j]`: Returns join keys between datasets `i` and `j`,</pre>
+                      <pre class="language-r">#' the variables specified by `names`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   including implicit keys inferred from their relationship with a parent.</pre>
+                      <pre class="language-r">#' This includes the final call that creates the variable(s) in question as well as all _parent calls_,</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' _i.e._ calls that create variables used in the final call and their parents, etc.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param i,j indices specifying elements to extract or replace. Index should be a</pre>
+                      <pre class="language-r">#' Also included are calls that create side-effects like establishing connections.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">12</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' a character vector, but it can also take numeric, logical, `NULL` or missing.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">13</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' It is assumed that object dependency is established by using three assignment operators: `&lt;-`, `=`, and `-&gt;` .</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">14</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">#' Other assignment methods (`assign`, `&lt;&lt;-`) or non-standard-evaluation methods are not supported.</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -712,21 +712,21 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">16</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">#' Side-effects are not detected automatically and must be marked in the code.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' Add `# @linksto object` at the end of a line where a side-effect occurs to specify that this line is required</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">18</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Getter for join_keys ---</pre>
+                      <pre class="language-r">#' to reproduce a variable called `object`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -740,21 +740,21 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">20</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk["ds1", "ds2"]</pre>
+                      <pre class="language-r">#' @param code `character` with the code.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">21</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @param names `character` vector of object names.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">22</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Subsetting join_keys ----</pre>
+                      <pre class="language-r">#' @param check_names `logical(1)` flag specifying if a warning for non-existing names should be displayed.</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -768,378 +768,378 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">24</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk["ds1"]</pre>
+                      <pre class="language-r">#' @return Character vector, a subset of `code`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">25</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk[1:2]</pre>
+                      <pre class="language-r">#' Note that subsetting is actually done on the calls `code`, not necessarily on the elements of the vector.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">26</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk[c("ds1", "ds2")]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">27</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">`[.join_keys` &lt;- function(x, i, j) {</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">28</td>
-                    <td class="coverage">31<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (missing(i) &amp;&amp; missing(j)) {</pre>
+                      <pre class="language-r">get_code_dependency &lt;- function(code, names, check_names = TRUE) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">29</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">42<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # because:</pre>
+                      <pre class="language-r">  checkmate::assert_character(code)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">30</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">42<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # - list(a = 1)[] returns list(a = 1)</pre>
+                      <pre class="language-r">  checkmate::assert_character(names, any.missing = FALSE)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">31</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # - data.frame(a = 1)[] returns data.frame(a = 1)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">32</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage">42<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(x)</pre>
+                      <pre class="language-r">  if (identical(code, character(0)) || identical(trimws(code), "")) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">33</td>
-                    <td class="coverage">30<em>x</em></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else if (!missing(i) &amp;&amp; is.null(i) || !missing(j) &amp;&amp; is.null(j)) {</pre>
+                      <pre class="language-r">    return(code)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">34</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # because list(a = 1)[NULL] returns NULL</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">35</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # data.frame(a = 1)[NULL, NULL] returns data.frame(</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">36</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(join_keys())</pre>
+                      <pre class="language-r">  code &lt;- parse(text = code, keep.source = TRUE)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">37</td>
-                    <td class="coverage">28<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else if (!missing(i) &amp;&amp; !missing(j)) {</pre>
+                      <pre class="language-r">  pd &lt;- utils::getParseData(code)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">38</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">39</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      !any(</pre>
+                      <pre class="language-r">  if (check_names) {</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">40</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        checkmate::test_string(i),</pre>
+                      <pre class="language-r">    # Detect if names are actually in code.</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">41</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        checkmate::test_number(i),</pre>
+                      <pre class="language-r">    symbols &lt;- unique(pd[pd$token == "SYMBOL", "text"])</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">42</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        checkmate::test_logical(i, len = length(x)) &amp;&amp; sum(j) == 1</pre>
+                      <pre class="language-r">    if (!all(names %in% symbols)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">43</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ) ||</pre>
+                      <pre class="language-r">      warning("Object(s) not found in code: ", toString(setdiff(names, symbols)))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">44</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        !any(</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">45</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">          checkmate::test_string(j),</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">46</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">          checkmate::test_number(j),</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">47</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">          checkmate::test_logical(j, len = length(x)) &amp;&amp; sum(j) == 1</pre>
+                      <pre class="language-r">  calls_pd &lt;- extract_calls(pd)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">48</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        )</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">49</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    ) {</pre>
+                      <pre class="language-r">  graph &lt;- code_graph(calls_pd)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">50</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      stop(</pre>
+                      <pre class="language-r">  ind &lt;- unlist(lapply(names, function(x) graph_parser(x, graph)))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">51</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        "join_keys[i, j] - Can't extract keys for multiple pairs.",</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">52</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        "When specifying a pair [i, j], both indices must point to a single key pair.\n",</pre>
+                      <pre class="language-r">  lib_ind &lt;- detect_libraries(calls_pd)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">53</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        call. = FALSE</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">54</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      )</pre>
+                      <pre class="language-r">  as.character(code[unique(c(lib_ind, ind))])</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">55</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">56</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (is.numeric(i)) i &lt;- names(x)[i]</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">57</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (is.numeric(j)) j &lt;- names(x)[j]</pre>
+                      <pre class="language-r">#' Split the result of `utils::getParseData()` into separate calls</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">58</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">59</td>
-                    <td class="coverage">8<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    subset_x &lt;- update_keys_given_parents(x[union(i, j)])</pre>
+                      <pre class="language-r">#' @param pd (`data.frame`) A result of `utils::getParseData()`.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">60</td>
-                    <td class="coverage">8<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(subset_x[[i]][[j]])</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">61</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else if (!missing(j)) {</pre>
+                      <pre class="language-r">#' @return</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">62</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # ie. select all keys which have j as dataset_2</pre>
+                      <pre class="language-r">#' A `list` of `data.frame`s.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">63</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # since list is symmetrical it is equivalent to selecting by i</pre>
+                      <pre class="language-r">#' Each element is a subset of `pd` corresponding to one call in the original code from which `pd` was obtained.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">64</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    i &lt;- j</pre>
+                      <pre class="language-r">#' Only four columns (`"token"`, `"text"`, `"id"`, `"parent"`) are kept, the rest is discarded.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">65</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">66</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">67</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert(</pre>
+                      <pre class="language-r">#' @noRd</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">68</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    combine = "or",</pre>
+                      <pre class="language-r">extract_calls &lt;- function(pd) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">69</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    checkmate::check_character(i),</pre>
+                      <pre class="language-r">  calls &lt;- lapply(pd[pd$parent == 0, "id"], get_children, pd = pd)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">70</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    checkmate::check_numeric(i),</pre>
+                      <pre class="language-r">  fix_comments(calls)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">71</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    checkmate::check_logical(i)</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">72</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">73</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">get_children &lt;- function(pd, parent) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">74</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1647<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  idx_children &lt;- abs(pd$parent) == parent</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">75</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1647<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Convert integer/logical index to named index</pre>
+                      <pre class="language-r">  children &lt;- pd[idx_children, c("token", "text", "id", "parent")]</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">76</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage">1647<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (checkmate::test_numeric(i) || checkmate::test_logical(i)) {</pre>
+                      <pre class="language-r">  if (nrow(children) == 0) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">77</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage">953<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    i &lt;- names(x)[i]</pre>
+                      <pre class="language-r">    return(NULL)</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -1156,32 +1156,32 @@ <h2>teal.data coverage - 78.35%</h2>
                       <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">80</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">694<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # When retrieving a relationship pair, it will also return the symmetric key</pre>
+                      <pre class="language-r">  if (parent &gt; 0) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">81</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage">694<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  new_jk &lt;- new_join_keys()</pre>
+                      <pre class="language-r">    do.call(rbind, c(list(children), lapply(children$id, get_children, pd = pd)))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">82</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  queue &lt;- unique(i)</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">83</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  bin &lt;- character(0)</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -1195,413 +1195,413 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">85</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Need to iterate on a mutating queue if subset of a dataset will also</pre>
+                      <pre class="language-r">fix_comments &lt;- function(calls) {</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">86</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  #  select its parent as that parent might have relationships with others</pre>
+                      <pre class="language-r">  # If the first token is a COMMENT, then it belongs to the previous call.</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">87</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  #  already selected.</pre>
+                      <pre class="language-r">  if (length(calls) &gt;= 2) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">88</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  while (length(queue) &gt; 0) {</pre>
+                      <pre class="language-r">    for (i in 2:length(calls)) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">89</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">101<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    ix &lt;- queue[1]</pre>
+                      <pre class="language-r">      if (grepl("@linksto", calls[[i]][1, "text"])) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">90</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    queue &lt;- queue[-1]</pre>
+                      <pre class="language-r">        calls[[i - 1]] &lt;- rbind(calls[[i - 1]], calls[[i]][1, ])</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">91</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    bin &lt;- c(bin, ix)</pre>
+                      <pre class="language-r">        calls[[i]] &lt;- calls[[i]][-1, ]</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">92</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">93</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    ix_parent &lt;- parent(x, ix)</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">94</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">95</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (checkmate::test_string(ix_parent, min.chars = 1) &amp;&amp; !ix_parent %in% c(queue, bin)) {</pre>
+                      <pre class="language-r">  calls</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">96</td>
-                    <td class="coverage">10<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      queue &lt;- c(queue, ix_parent)</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">97</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">98</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r"># code_graph ----</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">99</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    ix_valid_names &lt;- names(x[[ix]]) %in% c(queue, bin)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">100</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' Create Object Dependencies Graph Within Parsed Code</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">101</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    new_jk[[ix]] &lt;- x[[ix]][ix_valid_names]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">102</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @description</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">103</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # Add primary key of parent</pre>
+                      <pre class="language-r">#' Builds dependency graph that identifies dependencies between objects in parsed code.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">104</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (length(ix_parent) &gt; 0) {</pre>
+                      <pre class="language-r">#' Helps understand which objects depend on which.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">105</td>
-                    <td class="coverage">16<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      new_jk[[ix_parent]][[ix_parent]] &lt;- x[[ix_parent]][[ix_parent]]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">106</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">107</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">108</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">109</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  common_parents_ix &lt;- names(parents(x)) %in% names(new_jk) &amp;</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">110</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    parents(x) %in% names(new_jk)</pre>
+                      <pre class="language-r">#' @return</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">111</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' A list (of length of input `calls_pd`) where each element represents one call.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">112</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (any(common_parents_ix)) parents(new_jk) &lt;- parents(x)[common_parents_ix]</pre>
+                      <pre class="language-r">#' Each element is a character vector listing names of objects that depend on this call</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">113</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' and names of objects that this call depends on.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">114</td>
-                    <td class="coverage">19<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  new_jk</pre>
+                      <pre class="language-r">#' Dependencies are listed after the `"&lt;-"` string, e.g. `c("a", "&lt;-", "b", "c")` means that in this call object `a`</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">115</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#' depends on objects `b` and `c`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">116</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' If a call is tagged with `@linksto a`, then object `a` is understood to depend on that call.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">117</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">118</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 2</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">119</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @noRd</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">120</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param directed (`logical(1)`) Flag that indicates whether it should create</pre>
+                      <pre class="language-r">code_graph &lt;- function(calls_pd) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">121</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' a parent-child relationship between the datasets.\cr</pre>
+                      <pre class="language-r">  cooccurrence &lt;- extract_occurrence(calls_pd)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">122</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  - `TRUE` (default) `dataset_1` is the parent of `dataset_2`;</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">123</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  - `FALSE` when the relationship is undirected.</pre>
+                      <pre class="language-r">  side_effects &lt;- extract_side_effects(calls_pd)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">124</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @section Functions:</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">125</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `x[i, j] &lt;- value`: Assignment of a key to pair `(i, j)`.</pre>
+                      <pre class="language-r">  mapply(c, side_effects, cooccurrence, SIMPLIFY = FALSE)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">126</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `x[i] &lt;- value`: This (without `j` parameter) **is not** a supported</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">127</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' operation for `join_keys`.</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">128</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `join_keys(x)[i, j] &lt;- value`: Assignment to `join_keys` object stored in `x`,</pre>
+                      <pre class="language-r">#' Extract Object Occurrence</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">129</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' such as a `teal_data` or `join_keys` itself.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">130</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @description Extracts objects occurrence within calls passed by `calls_pd`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">131</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">#' Also detects which objects depend on which within a call.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">132</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">133</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">134</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Setting a new primary key ---</pre>
+                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">135</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">136</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk["ds4", "ds4"] &lt;- "pk4"</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">137</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk["ds5", "ds5"] &lt;- "pk5"</pre>
+                      <pre class="language-r">#' @return</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">138</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' A list (of length of input `calls_pd`) where each element represents one call.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">139</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Setting a single relationship pair ---</pre>
+                      <pre class="language-r">#' Each element is a character vector listing names of objects that depend on this call</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">140</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' and names of objects that this call depends on.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">141</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk["ds1", "ds4"] &lt;- c("pk1" = "pk4")</pre>
+                      <pre class="language-r">#' Dependencies are listed after the `"&lt;-"` string, e.g. `c("a", "&lt;-", "b", "c")` means that in this call object `a`</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">142</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' depends on objects `b` and `c`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">143</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Removing a key ---</pre>
+                      <pre class="language-r">#' If a call is tagged with `@linksto a`, then object `a` is understood to depend on that call.</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -1615,917 +1615,917 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">145</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk["ds5", "ds5"] &lt;- NULL</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">146</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">`[&lt;-.join_keys` &lt;- function(x, i, j, directed = TRUE, value) {</pre>
+                      <pre class="language-r">#' @noRd</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">147</td>
-                    <td class="coverage">11<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_flag(directed)</pre>
+                      <pre class="language-r">extract_occurrence &lt;- function(calls_pd) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">148</td>
-                    <td class="coverage">11<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (missing(i) || missing(j)) {</pre>
+                      <pre class="language-r">  is_in_function &lt;- function(x) {</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">149</td>
-                    <td class="coverage">4<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    stop("join_keys[i, j] specify both indices to set a key pair.")</pre>
+                      <pre class="language-r">    # If an object is a function parameter,</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">150</td>
-                    <td class="coverage">7<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else if (!missing(i) &amp;&amp; is.null(i) || !missing(j) &amp;&amp; is.null(j)) {</pre>
+                      <pre class="language-r">    # then in calls_pd there is a `SYMBOL_FORMALS` entry for that object.</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">151</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage">133<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    stop("join_keys[i, j] neither i nor j can be NULL.")</pre>
+                      <pre class="language-r">    function_id &lt;- x[x$token == "FUNCTION", "parent"]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">152</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">133<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else if (</pre>
+                      <pre class="language-r">    if (length(function_id)) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">153</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    !any(</pre>
+                      <pre class="language-r">      x$id %in% get_children(x, function_id)$id</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">154</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      checkmate::test_string(i),</pre>
+                      <pre class="language-r">    } else {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">155</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage">124<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      checkmate::test_number(i),</pre>
+                      <pre class="language-r">      rep(FALSE, nrow(x))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">156</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      checkmate::test_logical(i, len = length(x)) &amp;&amp; sum(j) == 1</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">157</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    ) ||</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">158</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      !any(</pre>
+                      <pre class="language-r">  lapply(</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">159</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        checkmate::test_string(j),</pre>
+                      <pre class="language-r">    calls_pd,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">160</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        checkmate::test_number(j),</pre>
+                      <pre class="language-r">    function(call_pd) {</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">161</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        checkmate::test_logical(j, len = length(x)) &amp;&amp; sum(j) == 1</pre>
+                      <pre class="language-r">      # Handle data(object)/data("object")/data(object, envir = ) independently.</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">162</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">141<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      )</pre>
+                      <pre class="language-r">      data_call &lt;- call_pd$token == "SYMBOL_FUNCTION_CALL" &amp; call_pd$text == "data"</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">163</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">141<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  ) {</pre>
+                      <pre class="language-r">      if (any(data_call)) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">164</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    stop(</pre>
+                      <pre class="language-r">        sym &lt;- call_pd[which(data_call) + 1, "text"]</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">165</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      "join_keys[i, j] &lt;- Can't set keys to specified indices.\n",</pre>
+                      <pre class="language-r">        return(c(gsub("'", "", sym), "&lt;-", "data"))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">166</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      "When setting pair [i, j], both indices must point to a single key pair.\n",</pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">167</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      call. = FALSE</pre>
+                      <pre class="language-r">      # Handle assign().</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">168</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">138<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    )</pre>
+                      <pre class="language-r">      assign_call &lt;- call_pd$token == "SYMBOL_FUNCTION_CALL" &amp; call_pd$text == "assign"</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">169</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">138<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">      if (any(assign_call)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">170</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">        call_pd_lim &lt;- call_pd[-c(1:which(assign_call)), ]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">171</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Handle join key removal separately</pre>
+                      <pre class="language-r">        sym &lt;- call_pd_lim[call_pd_lim$token == "STR_CONST", "text"]</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">172</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (is.null(value)) {</pre>
+                      <pre class="language-r">        return(c(gsub("'", "", sym), "&lt;-", "assign"))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">173</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    x[[i]][[j]] &lt;- NULL</pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">174</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(x)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">175</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">      # What occurs in a function body is not tracked.</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">176</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">133<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">      x &lt;- call_pd[!is_in_function(call_pd), ]</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">177</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage">133<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  c(x, join_key(i, j, value, directed))</pre>
+                      <pre class="language-r">      sym_cond &lt;- which(x$token %in% c("SYMBOL", "SYMBOL_FUNCTION_CALL"))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">178</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">179</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">133<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">      if (length(sym_cond) == 0) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">180</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @noRd</pre>
+                      <pre class="language-r">        return(character(0))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">181</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">182</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      # Watch out for SYMBOLS after $ and @. For x$a x@a: x is object, a is not.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">183</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 1000</pre>
+                      <pre class="language-r">      # For x$a, a's ID is $'s ID-2 so we need to remove all IDs that have ID = $ID - 2.</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">184</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">131<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @usage ## Prefered method is x[i, j] &lt;- value</pre>
+                      <pre class="language-r">      dollar_ids &lt;- x[x$token %in% c("'$'", "'@'"), "id"]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">185</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">131<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' x[[i]][[j]] &lt;- value</pre>
+                      <pre class="language-r">      if (length(dollar_ids)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">186</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">12<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">        object_ids &lt;- x[sym_cond, "id"]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">187</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">12<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @section Functions:</pre>
+                      <pre class="language-r">        after_dollar &lt;- object_ids[(object_ids - 2) %in% dollar_ids]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">188</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">12<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `x[[i]][[j]] &lt;- value`: It is equivalent as  `x[i, j] &lt;- value`.</pre>
+                      <pre class="language-r">        sym_cond &lt;- setdiff(sym_cond, which(x$id %in% after_dollar))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">189</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">190</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">191</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">      # If there was an assignment operation detect direction of it.</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">192</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">131<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      ass_cond &lt;- grep("ASSIGN", x$token)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">193</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">131<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Setting via x[[i]] &lt;- value ---</pre>
+                      <pre class="language-r">      if (length(ass_cond)) { # NOTE 1</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">194</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">115<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">        sym_cond &lt;- sym_cond[sym_cond &gt; ass_cond] # NOTE 2</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">195</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk &lt;- join_keys()</pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">196</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">131<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk[["ds6"]][["ds6"]] &lt;- "pk6"</pre>
+                      <pre class="language-r">      if ((length(ass_cond) &amp;&amp; x$text[ass_cond] == "-&gt;") || !length(ass_cond)) { # NOTE 3</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">197</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">18<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk[["ds7"]] &lt;- list(ds7 = "pk7", ds6 = c(pk7 = "pk6"))</pre>
+                      <pre class="language-r">        sym_cond &lt;- rev(sym_cond)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">198</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk[["ds7"]][["ds7"]] &lt;- NULL # removes key</pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">199</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">131<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      append(unique(x[sym_cond, "text"]), "&lt;-", after = 1)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">200</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">201</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">`[[&lt;-.join_keys` &lt;- function(x, i, value) {</pre>
+                      <pre class="language-r">      ### NOTE 3: What if there are 2+ assignments, e.g. a &lt;- b -&gt; c or e.g. a &lt;- b &lt;- c.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">202</td>
-                    <td class="coverage">380<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert(</pre>
+                      <pre class="language-r">      ### NOTE 2: For cases like 'eval(expression(b &lt;- b + 2))' removes 'eval(expression('.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">203</td>
-                    <td class="coverage">380<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    combine = "or",</pre>
+                      <pre class="language-r">      ### NOTE 1: Cases like 'data(iris)' that do not have an assignment operator.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">204</td>
-                    <td class="coverage">380<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    checkmate::check_string(i),</pre>
+                      <pre class="language-r">      ### NOTE 1: Then they are parsed as c("iris", "&lt;-", "data")</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">205</td>
-                    <td class="coverage">380<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    checkmate::check_number(i),</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">206</td>
-                    <td class="coverage">380<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    checkmate::check_logical(i, len = length(x))</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">207</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">208</td>
-                    <td class="coverage">380<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_list(value, names = "named", types = "character", null.ok = TRUE)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">209</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (checkmate::test_numeric(i) || checkmate::test_logical(i)) {</pre>
+                      <pre class="language-r">#' Extract Side Effects</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">210</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    i &lt;- names(x)[[i]]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">211</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#' @description Extracts all object names from the code that are marked with `@linksto` tag.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">212</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">213</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Normalize values</pre>
+                      <pre class="language-r">#' @details</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">214</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  norm_value &lt;- lapply(seq_along(value), function(.x) {</pre>
+                      <pre class="language-r">#' The code may contain functions calls that create side effects, e.g. modify the environment.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">215</td>
-                    <td class="coverage">522<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    join_key(i, names(value)[.x], value[[.x]])</pre>
+                      <pre class="language-r">#' Static code analysis may be insufficient to determine which objects are created or modified by such a function call.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">216</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  })</pre>
+                      <pre class="language-r">#' The `@linksto` comment tag is introduced to mark a call as having a (side) effect on one or more objects.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">217</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  names(norm_value) &lt;- names(value)</pre>
+                      <pre class="language-r">#' With this tag a complete object dependency structure can be established.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">218</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' Read more about side effects and the usage of `@linksto` tag in [`get_code_dependencies()`] function.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">219</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Check if multiple modifications don't have a conflict</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">220</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  repeated_value_ix &lt;- names(value) %in% names(value)[duplicated(names(value))]</pre>
+                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">221</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  repeated &lt;- norm_value[repeated_value_ix]</pre>
+                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">222</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  vapply(</pre>
+                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">223</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    seq_along(repeated),</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">224</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    function(.ix, .x_value = repeated[[.ix]], .x_name = names(.x_value[[1]])) {</pre>
+                      <pre class="language-r">#' @return</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">225</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      assert_compatible_keys2(</pre>
+                      <pre class="language-r">#' A list of length equal to that of `calls_pd`, where each element is a character vector of names of objects</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">226</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        .x_value,</pre>
+                      <pre class="language-r">#' depending a call tagged with `@linksto` in a corresponding element of `calls_pd`.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">227</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        unlist(unname(</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">228</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">          repeated[-.ix][names(repeated[-.ix]) == .x_name]</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">229</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        ), recursive = FALSE)</pre>
+                      <pre class="language-r">#' @noRd</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">230</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      )</pre>
+                      <pre class="language-r">extract_side_effects &lt;- function(calls_pd) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">231</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    },</pre>
+                      <pre class="language-r">  lapply(</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">232</td>
-                    <td class="coverage">373<em>x</em></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    logical(1)</pre>
+                      <pre class="language-r">    calls_pd,</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">233</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">    function(x) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">234</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">141<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">      linksto &lt;- grep("@linksto", x[x$token == "COMMENT", "text"], value = TRUE)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">235</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage">141<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  norm_value &lt;- lapply(norm_value, function(x) x[[1]][[1]])</pre>
+                      <pre class="language-r">      unlist(strsplit(sub("\\s*#\\s*@linksto\\s+", "", linksto), "\\s+"))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">236</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  names(norm_value) &lt;- names(value)</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">237</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">238</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Safe to do as duplicated are the same</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">239</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  norm_value[duplicated(names(norm_value))] &lt;- NULL</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">240</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r"># graph_parser ----</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">241</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Keep only elements with length &gt; 0L</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">242</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  norm_value &lt;- Filter(length, norm_value)</pre>
+                      <pre class="language-r">#' Return the indices of calls needed to reproduce an object</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">243</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">244</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Remove classes to use list-based get/assign operations</pre>
+                      <pre class="language-r">#' @param x The name of the object to return code for.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">245</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  new_x &lt;- unclass(x)</pre>
+                      <pre class="language-r">#' @param graph A result of `code_graph()`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">246</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">247</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # In case a pair is removed, also remove the symmetric pair and update parents</pre>
+                      <pre class="language-r">#' @return</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">248</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  removed_names &lt;- setdiff(names(new_x[[i]]), names(norm_value))</pre>
+                      <pre class="language-r">#' Integer vector of indices that can be applied to `graph` to obtain all calls required to reproduce object `x`.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">249</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  for (.x in removed_names) {</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">250</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (identical(parent(x, .x), i)) attr(new_x, "parents")[[.x]] &lt;- NULL</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">251</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (identical(parent(x, i), .x)) attr(new_x, "parents")[[i]] &lt;- NULL</pre>
+                      <pre class="language-r">#' @noRd</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">252</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">graph_parser &lt;- function(x, graph) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">253</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage">178<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    new_x[[.x]][[i]] &lt;- NULL</pre>
+                      <pre class="language-r">  occurrence &lt;- vapply(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">254</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">178<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">    graph, function(call) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">255</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">514<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">      ind &lt;- match("&lt;-", call, nomatch = length(call) + 1L)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">256</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage">514<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  new_x[[i]] &lt;- norm_value</pre>
+                      <pre class="language-r">      x %in% call[seq_len(ind - 1L)]</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">257</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    },</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">258</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">178<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Iterate on all new values to create symmetrical pair</pre>
+                      <pre class="language-r">    logical(1)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">259</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  for (ds2 in names(norm_value)) {</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">260</td>
-                    <td class="coverage">297<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (ds2 == i) next</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">261</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">178<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  dependencies &lt;- lapply(graph[occurrence], function(call) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">262</td>
-                    <td class="coverage">221<em>x</em></td>
+                    <td class="coverage">95<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    keep_value &lt;- if (is.null(x)) list() else new_x[[ds2]]</pre>
+                      <pre class="language-r">    ind &lt;- match("&lt;-", call, nomatch = 0L)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">263</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">95<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    call[(ind + 1L):length(call)]</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">264</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # Invert key</pre>
+                      <pre class="language-r">  })</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">265</td>
-                    <td class="coverage">221<em>x</em></td>
+                    <td class="coverage">178<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    new_value &lt;- stats::setNames(names(norm_value[[ds2]]), norm_value[[ds2]])</pre>
+                      <pre class="language-r">  dependencies &lt;- setdiff(unlist(dependencies), x)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">266</td>
-                    <td class="coverage">221<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    keep_value[[i]] &lt;- new_value</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">267</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">178<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  if (length(dependencies) &amp;&amp; any(occurrence)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">268</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">67<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # Assign symmetrical</pre>
+                      <pre class="language-r">    dependency_ids &lt;- lapply(dependencies, function(dependency) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">269</td>
-                    <td class="coverage">221<em>x</em></td>
+                    <td class="coverage">136<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    new_x[[ds2]] &lt;- keep_value</pre>
+                      <pre class="language-r">      graph_parser(dependency, graph[1:max(which(occurrence))])</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">270</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">    })</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">271</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">67<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    sort(unique(c(which(occurrence), unlist(dependency_ids))))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">272</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  preserve_attr &lt;- attributes(new_x)[!names(attributes(new_x)) %in% "names"]</pre>
+                      <pre class="language-r">  } else {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">273</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">111<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Remove NULL or empty keys</pre>
+                      <pre class="language-r">    which(occurrence)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">274</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  new_x &lt;- Filter(function(x) length(x) != 0L, new_x)</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">275</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  attributes(new_x) &lt;- utils::modifyList(attributes(new_x), preserve_attr)</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -2539,2332 +2539,2521 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">277</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  #</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">278</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # restore class</pre>
+                      <pre class="language-r"># default_side_effects --------------------------------------------------------------------------------------------</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">279</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  class(new_x) &lt;- class(x)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">280</td>
-                    <td class="coverage">372<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  new_x</pre>
+                      <pre class="language-r">#' Detect Library Calls</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">281</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                </tbody>
-              </table>
-            </div>
-            <div id="R/utils-get_code_dependency.R" class="hidden">
-              <table class="table-condensed">
-                <tbody>
                   <tr class="never">
-                    <td class="num">1</td>
+                    <td class="num">282</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"># get_code_dependency ----</pre>
+                      <pre class="language-r">#' Detects `library()` and `require()` function calls.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">2</td>
+                    <td class="num">283</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">3</td>
+                    <td class="num">284</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Get Code Dependency of an Object</pre>
+                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">4</td>
+                    <td class="num">285</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">5</td>
+                    <td class="num">286</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Extract subset of code required to reproduce specific object(s), including code producing side-effects.</pre>
+                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">6</td>
+                    <td class="num">287</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">7</td>
+                    <td class="num">288</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Given a character vector with code, this function will extract the part of the code responsible for creating</pre>
+                      <pre class="language-r">#' @return</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">8</td>
+                    <td class="num">289</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' the variables specified by `names`.</pre>
+                      <pre class="language-r">#' Integer vector of indices that can be applied to `graph` (result of `code_graph()`) to obtain all calls containing</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">9</td>
+                    <td class="num">290</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' This includes the final call that creates the variable(s) in question as well as all _parent calls_,</pre>
+                      <pre class="language-r">#' `library()` or `require()` calls that are always returned for reproducibility.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">10</td>
+                    <td class="num">291</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' _i.e._ calls that create variables used in the final call and their parents, etc.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">11</td>
+                    <td class="num">292</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Also included are calls that create side-effects like establishing connections.</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">12</td>
+                    <td class="num">293</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @noRd</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">13</td>
+                    <td class="num">294</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' It is assumed that object dependency is established by using three assignment operators: `&lt;-`, `=`, and `-&gt;` .</pre>
+                      <pre class="language-r">detect_libraries &lt;- function(calls_pd) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">14</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">295</td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Other assignment methods (`assign`, `&lt;&lt;-`) or non-standard-evaluation methods are not supported.</pre>
+                      <pre class="language-r">  defaults &lt;- c("library", "require")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">15</td>
+                    <td class="num">296</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">16</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">297</td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Side-effects are not detected automatically and must be marked in the code.</pre>
+                      <pre class="language-r">  which(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">17</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">298</td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Add `# @linksto object` at the end of a line where a side-effect occurs to specify that this line is required</pre>
+                      <pre class="language-r">    vapply(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">18</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">299</td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' to reproduce a variable called `object`.</pre>
+                      <pre class="language-r">      calls_pd,</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">19</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">300</td>
+                    <td class="coverage">40<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      function(call) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">20</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">301</td>
+                    <td class="coverage">141<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param code `character` with the code.</pre>
+                      <pre class="language-r">        any(call$token == "SYMBOL_FUNCTION_CALL" &amp; call$text %in% defaults)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">21</td>
+                    <td class="num">302</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param names `character` vector of object names.</pre>
+                      <pre class="language-r">      },</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">303</td>
+                    <td class="coverage">40<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">      logical(1)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">22</td>
+                    <td class="num">304</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param check_names `logical(1)` flag specifying if a warning for non-existing names should be displayed.</pre>
+                      <pre class="language-r">    )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">23</td>
+                    <td class="num">305</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">24</td>
+                    <td class="num">306</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return Character vector, a subset of `code`.</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
+                </tbody>
+              </table>
+            </div>
+            <div id="R/utils.R" class="hidden">
+              <table class="table-condensed">
+                <tbody>
                   <tr class="never">
-                    <td class="num">25</td>
+                    <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Note that subsetting is actually done on the calls `code`, not necessarily on the elements of the vector.</pre>
+                      <pre class="language-r">#' Whether the variable name is good to use within Show R Code</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">26</td>
+                    <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">27</td>
+                    <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">#' Spaces are problematic because the variables must be escaped</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">28</td>
+                    <td class="num">4</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">get_code_dependency &lt;- function(code, names, check_names = TRUE) {</pre>
+                      <pre class="language-r">#' with backticks.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">29</td>
-                    <td class="coverage">40<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">5</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_character(code)</pre>
+                      <pre class="language-r">#' Also, they should not start with a number as R may silently make</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">30</td>
-                    <td class="coverage">40<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">6</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_character(names, any.missing = FALSE)</pre>
+                      <pre class="language-r">#' it valid by changing it.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">31</td>
+                    <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' Therefore, we only allow alphanumeric characters with underscores.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">32</td>
-                    <td class="coverage">40<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">8</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (identical(code, character(0)) || identical(trimws(code), "")) {</pre>
+                      <pre class="language-r">#' The first character of the `name` must be an alphabetic character</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">33</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">9</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(code)</pre>
+                      <pre class="language-r">#' and can be followed by alphanumeric characters.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">34</td>
+                    <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">35</td>
+                    <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @md</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">36</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">12</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  code &lt;- parse(text = code, keep.source = TRUE)</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">37</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">13</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  pd &lt;- utils::getParseData(code)</pre>
+                      <pre class="language-r">#' @param name `character, single or vector` name to check</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">38</td>
+                    <td class="num">14</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">39</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">15</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (check_names) {</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">40</td>
+                    <td class="num">16</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # Detect if names are actually in code.</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">41</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">17</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    symbols &lt;- unique(pd[pd$token == "SYMBOL", "text"])</pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("aas2df")</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">42</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">18</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (!all(names %in% symbols)) {</pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL")</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">43</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">19</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      warning("Object(s) not found in code: ", toString(setdiff(names, symbols)))</pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("ADSLmodified")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">44</td>
+                    <td class="num">20</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL_2")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">45</td>
+                    <td class="num">21</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("a1")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">46</td>
+                    <td class="num">22</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' # the following fail</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">47</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">23</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  calls_pd &lt;- extract_calls(pd)</pre>
+                      <pre class="language-r">#' \dontrun{</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">48</td>
+                    <td class="num">24</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("1a")</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">49</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">25</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  graph &lt;- code_graph(calls_pd)</pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL.modified")</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">50</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">26</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  ind &lt;- unlist(lapply(names, function(x) graph_parser(x, graph)))</pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL_modified")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">51</td>
+                    <td class="num">27</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' teal.data:::check_simple_name("a1...")</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">52</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">28</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  lib_ind &lt;- detect_libraries(calls_pd)</pre>
+                      <pre class="language-r">#' }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">53</td>
+                    <td class="num">29</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">check_simple_name &lt;- function(name) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">54</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">30</td>
+                    <td class="coverage">16<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  as.character(code[unique(c(lib_ind, ind))])</pre>
+                      <pre class="language-r">  checkmate::assert_character(name, min.len = 1, any.missing = FALSE)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">55</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">31</td>
+                    <td class="coverage">16<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">  if (!grepl("^[[:alpha:]][a-zA-Z0-9_]*$", name, perl = TRUE)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">56</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">32</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    checkmate::makeAssertion(</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">33</td>
+                    <td class="coverage">5<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">      name,</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">34</td>
+                    <td class="coverage">5<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">      paste0(</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">57</td>
+                    <td class="num">35</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Split the result of `utils::getParseData()` into separate calls</pre>
+                      <pre class="language-r">        "'",</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">36</td>
+                    <td class="coverage">5<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">        name,</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">58</td>
+                    <td class="num">37</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">        "' ",</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">38</td>
+                    <td class="coverage">5<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">        "must only contain alphanumeric characters (with underscores)",</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">39</td>
+                    <td class="coverage">5<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">        " and the first character must be an alphabetic character"</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">59</td>
+                    <td class="num">40</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param pd (`data.frame`) A result of `utils::getParseData()`.</pre>
+                      <pre class="language-r">      ),</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">41</td>
+                    <td class="coverage">5<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">      var.name = "name",</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">42</td>
+                    <td class="coverage">5<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">      NULL</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">60</td>
+                    <td class="num">43</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">61</td>
+                    <td class="num">44</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">62</td>
+                    <td class="num">45</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' A `list` of `data.frame`s.</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
+                </tbody>
+              </table>
+            </div>
+            <div id="R/join_keys-extract.R" class="hidden">
+              <table class="table-condensed">
+                <tbody>
                   <tr class="never">
-                    <td class="num">63</td>
+                    <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Each element is a subset of `pd` corresponding to one call in the original code from which `pd` was obtained.</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">64</td>
+                    <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Only four columns (`"token"`, `"text"`, `"id"`, `"parent"`) are kept, the rest is discarded.</pre>
+                      <pre class="language-r">#' @order 2</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">65</td>
+                    <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">66</td>
+                    <td class="num">4</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">#' @section Functions:</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">67</td>
+                    <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @noRd</pre>
+                      <pre class="language-r">#' - `x[datanames]`: Returns a subset of the `join_keys` object for</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">68</td>
+                    <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">extract_calls &lt;- function(pd) {</pre>
+                      <pre class="language-r">#' given `datanames`, including parent `datanames` and symmetric mirror keys between</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">69</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">7</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  calls &lt;- lapply(pd[pd$parent == 0, "id"], get_children, pd = pd)</pre>
+                      <pre class="language-r">#' `datanames` in the result.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">70</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">8</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  fix_comments(calls)</pre>
+                      <pre class="language-r">#' - `x[i, j]`: Returns join keys between datasets `i` and `j`,</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">71</td>
+                    <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#'   including implicit keys inferred from their relationship with a parent.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">72</td>
+                    <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">73</td>
+                    <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">get_children &lt;- function(pd, parent) {</pre>
+                      <pre class="language-r">#' @param i,j indices specifying elements to extract or replace. Index should be a</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">74</td>
-                    <td class="coverage">1555<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">12</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  idx_children &lt;- abs(pd$parent) == parent</pre>
+                      <pre class="language-r">#' a character vector, but it can also take numeric, logical, `NULL` or missing.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">75</td>
-                    <td class="coverage">1555<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">13</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  children &lt;- pd[idx_children, c("token", "text", "id", "parent")]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">76</td>
-                    <td class="coverage">1555<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">14</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (nrow(children) == 0) {</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">77</td>
-                    <td class="coverage">899<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">15</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(NULL)</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">78</td>
+                    <td class="num">16</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">79</td>
+                    <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">80</td>
-                    <td class="coverage">656<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">18</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (parent &gt; 0) {</pre>
+                      <pre class="language-r">#' # Getter for join_keys ---</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">81</td>
-                    <td class="coverage">656<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">19</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    do.call(rbind, c(list(children), lapply(children$id, get_children, pd = pd)))</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">82</td>
+                    <td class="num">20</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#' jk["ds1", "ds2"]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">83</td>
+                    <td class="num">21</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">84</td>
+                    <td class="num">22</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' # Subsetting join_keys ----</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">85</td>
+                    <td class="num">23</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">fix_comments &lt;- function(calls) {</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">86</td>
+                    <td class="num">24</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # If the first token is a COMMENT, then it belongs to the previous call.</pre>
+                      <pre class="language-r">#' jk["ds1"]</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">87</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">25</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (length(calls) &gt;= 2) {</pre>
+                      <pre class="language-r">#' jk[1:2]</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">88</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">26</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    for (i in 2:length(calls)) {</pre>
+                      <pre class="language-r">#' jk[c("ds1", "ds2")]</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">89</td>
-                    <td class="coverage">93<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">27</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      if (grepl("@linksto", calls[[i]][1, "text"])) {</pre>
+                      <pre class="language-r">`[.join_keys` &lt;- function(x, i, j) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">90</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="num">28</td>
+                    <td class="coverage">31<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        calls[[i - 1]] &lt;- rbind(calls[[i - 1]], calls[[i]][1, ])</pre>
+                      <pre class="language-r">  if (missing(i) &amp;&amp; missing(j)) {</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">91</td>
-                    <td class="coverage">3<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">29</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        calls[[i]] &lt;- calls[[i]][-1, ]</pre>
+                      <pre class="language-r">    # because:</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">92</td>
+                    <td class="num">30</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      }</pre>
+                      <pre class="language-r">    # - list(a = 1)[] returns list(a = 1)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">93</td>
+                    <td class="num">31</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">    # - data.frame(a = 1)[] returns data.frame(a = 1)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">94</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">32</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">    return(x)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">95</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">33</td>
+                    <td class="coverage">30<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  calls</pre>
+                      <pre class="language-r">  } else if (!missing(i) &amp;&amp; is.null(i) || !missing(j) &amp;&amp; is.null(j)) {</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">96</td>
+                    <td class="num">34</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">    # because list(a = 1)[NULL] returns NULL</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">97</td>
+                    <td class="num">35</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    # data.frame(a = 1)[NULL, NULL] returns data.frame(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">98</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">36</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"># code_graph ----</pre>
+                      <pre class="language-r">    return(join_keys())</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">99</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">37</td>
+                    <td class="coverage">28<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  } else if (!missing(i) &amp;&amp; !missing(j)) {</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">100</td>
+                    <td class="num">38</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Create Object Dependencies Graph Within Parsed Code</pre>
+                      <pre class="language-r">    if (</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">101</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">39</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      !any(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">102</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">40</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @description</pre>
+                      <pre class="language-r">        checkmate::test_string(i),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">103</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">41</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Builds dependency graph that identifies dependencies between objects in parsed code.</pre>
+                      <pre class="language-r">        checkmate::test_number(i),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">104</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">42</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Helps understand which objects depend on which.</pre>
+                      <pre class="language-r">        checkmate::test_logical(i, len = length(x)) &amp;&amp; sum(j) == 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">105</td>
+                    <td class="num">43</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      ) ||</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">106</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">44</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
+                      <pre class="language-r">        !any(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">107</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">45</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
+                      <pre class="language-r">          checkmate::test_string(j),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">108</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">46</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
+                      <pre class="language-r">          checkmate::test_number(j),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">109</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">47</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">          checkmate::test_logical(j, len = length(x)) &amp;&amp; sum(j) == 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">110</td>
+                    <td class="num">48</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return</pre>
+                      <pre class="language-r">        )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">111</td>
+                    <td class="num">49</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' A list (of length of input `calls_pd`) where each element represents one call.</pre>
+                      <pre class="language-r">    ) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">112</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">50</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Each element is a character vector listing names of objects that depend on this call</pre>
+                      <pre class="language-r">      stop(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">113</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">51</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' and names of objects that this call depends on.</pre>
+                      <pre class="language-r">        "join_keys[i, j] - Can't extract keys for multiple pairs.",</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">114</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">52</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Dependencies are listed after the `"&lt;-"` string, e.g. `c("a", "&lt;-", "b", "c")` means that in this call object `a`</pre>
+                      <pre class="language-r">        "When specifying a pair [i, j], both indices must point to a single key pair.\n",</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">115</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">53</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' depends on objects `b` and `c`.</pre>
+                      <pre class="language-r">        call. = FALSE</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">116</td>
+                    <td class="num">54</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' If a call is tagged with `@linksto a`, then object `a` is understood to depend on that call.</pre>
+                      <pre class="language-r">      )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">117</td>
+                    <td class="num">55</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">118</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">56</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">    if (is.numeric(i)) i &lt;- names(x)[i]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">119</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">57</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @noRd</pre>
+                      <pre class="language-r">    if (is.numeric(j)) j &lt;- names(x)[j]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">120</td>
+                    <td class="num">58</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">code_graph &lt;- function(calls_pd) {</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">121</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">59</td>
+                    <td class="coverage">8<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  cooccurrence &lt;- extract_occurrence(calls_pd)</pre>
+                      <pre class="language-r">    subset_x &lt;- update_keys_given_parents(x[union(i, j)])</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">122</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">60</td>
+                    <td class="coverage">8<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    return(subset_x[[i]][[j]])</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">123</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">61</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  side_effects &lt;- extract_side_effects(calls_pd)</pre>
+                      <pre class="language-r">  } else if (!missing(j)) {</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">124</td>
+                    <td class="num">62</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    # ie. select all keys which have j as dataset_2</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">63</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">    # since list is symmetrical it is equivalent to selecting by i</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">125</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">64</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  mapply(c, side_effects, cooccurrence, SIMPLIFY = FALSE)</pre>
+                      <pre class="language-r">    i &lt;- j</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">126</td>
+                    <td class="num">65</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">127</td>
+                    <td class="num">66</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">128</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">67</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Extract Object Occurrence</pre>
+                      <pre class="language-r">  checkmate::assert(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">129</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">68</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    combine = "or",</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">130</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">69</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @description Extracts objects occurrence within calls passed by `calls_pd`.</pre>
+                      <pre class="language-r">    checkmate::check_character(i),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">131</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">70</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Also detects which objects depend on which within a call.</pre>
+                      <pre class="language-r">    checkmate::check_numeric(i),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">132</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">71</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    checkmate::check_logical(i)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">133</td>
+                    <td class="num">72</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">134</td>
+                    <td class="num">73</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">135</td>
+                    <td class="num">74</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">136</td>
+                    <td class="num">75</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  # Convert integer/logical index to named index</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">137</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">76</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return</pre>
+                      <pre class="language-r">  if (checkmate::test_numeric(i) || checkmate::test_logical(i)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">138</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">77</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' A list (of length of input `calls_pd`) where each element represents one call.</pre>
+                      <pre class="language-r">    i &lt;- names(x)[i]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">139</td>
+                    <td class="num">78</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Each element is a character vector listing names of objects that depend on this call</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">140</td>
+                    <td class="num">79</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' and names of objects that this call depends on.</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">141</td>
+                    <td class="num">80</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Dependencies are listed after the `"&lt;-"` string, e.g. `c("a", "&lt;-", "b", "c")` means that in this call object `a`</pre>
+                      <pre class="language-r">  # When retrieving a relationship pair, it will also return the symmetric key</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">142</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">81</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' depends on objects `b` and `c`.</pre>
+                      <pre class="language-r">  new_jk &lt;- new_join_keys()</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">143</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">82</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' If a call is tagged with `@linksto a`, then object `a` is understood to depend on that call.</pre>
+                      <pre class="language-r">  queue &lt;- unique(i)</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">83</td>
+                    <td class="coverage">19<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  bin &lt;- character(0)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">144</td>
+                    <td class="num">84</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">145</td>
+                    <td class="num">85</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">  # Need to iterate on a mutating queue if subset of a dataset will also</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">146</td>
+                    <td class="num">86</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @noRd</pre>
+                      <pre class="language-r">  #  select its parent as that parent might have relationships with others</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">147</td>
+                    <td class="num">87</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">extract_occurrence &lt;- function(calls_pd) {</pre>
+                      <pre class="language-r">  #  already selected.</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">148</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">88</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  is_in_function &lt;- function(x) {</pre>
+                      <pre class="language-r">  while (length(queue) &gt; 0) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">149</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">89</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # If an object is a function parameter,</pre>
+                      <pre class="language-r">    ix &lt;- queue[1]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">150</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">90</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    # then in calls_pd there is a `SYMBOL_FORMALS` entry for that object.</pre>
+                      <pre class="language-r">    queue &lt;- queue[-1]</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">151</td>
-                    <td class="coverage">128<em>x</em></td>
+                    <td class="num">91</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    function_id &lt;- x[x$token == "FUNCTION", "parent"]</pre>
+                      <pre class="language-r">    bin &lt;- c(bin, ix)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">152</td>
-                    <td class="coverage">128<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">92</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (length(function_id)) {</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">153</td>
-                    <td class="coverage">9<em>x</em></td>
+                    <td class="num">93</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      x$id %in% get_children(x, function_id)$id</pre>
+                      <pre class="language-r">    ix_parent &lt;- parent(x, ix)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">154</td>
+                    <td class="num">94</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    } else {</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">155</td>
-                    <td class="coverage">119<em>x</em></td>
+                    <td class="num">95</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      rep(FALSE, nrow(x))</pre>
+                      <pre class="language-r">    if (checkmate::test_string(ix_parent, min.chars = 1) &amp;&amp; !ix_parent %in% c(queue, bin)) {</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">96</td>
+                    <td class="coverage">10<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">      queue &lt;- c(queue, ix_parent)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">156</td>
+                    <td class="num">97</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">157</td>
+                    <td class="num">98</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">158</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">99</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  lapply(</pre>
+                      <pre class="language-r">    ix_valid_names &lt;- names(x[[ix]]) %in% c(queue, bin)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">159</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">100</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    calls_pd,</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">160</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">101</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    function(call_pd) {</pre>
+                      <pre class="language-r">    new_jk[[ix]] &lt;- x[[ix]][ix_valid_names]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">161</td>
+                    <td class="num">102</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      # Handle data(object)/data("object")/data(object, envir = ) independently.</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">162</td>
-                    <td class="coverage">131<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">      data_call &lt;- call_pd$token == "SYMBOL_FUNCTION_CALL" &amp; call_pd$text == "data"</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">163</td>
-                    <td class="coverage">131<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">103</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      if (any(data_call)) {</pre>
+                      <pre class="language-r">    # Add primary key of parent</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">164</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="num">104</td>
+                    <td class="coverage">44<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        sym &lt;- call_pd[which(data_call) + 1, "text"]</pre>
+                      <pre class="language-r">    if (length(ix_parent) &gt; 0) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">165</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="num">105</td>
+                    <td class="coverage">16<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        return(c(gsub("'", "", sym), "&lt;-", "data"))</pre>
+                      <pre class="language-r">      new_jk[[ix_parent]][[ix_parent]] &lt;- x[[ix_parent]][[ix_parent]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">166</td>
+                    <td class="num">106</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      }</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">167</td>
+                    <td class="num">107</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">168</td>
+                    <td class="num">108</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      # What occurs in a function body is not tracked.</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">169</td>
-                    <td class="coverage">128<em>x</em></td>
+                    <td class="num">109</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      x &lt;- call_pd[!is_in_function(call_pd), ]</pre>
+                      <pre class="language-r">  common_parents_ix &lt;- names(parents(x)) %in% names(new_jk) &amp;</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">170</td>
-                    <td class="coverage">128<em>x</em></td>
+                    <td class="num">110</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      sym_cond &lt;- which(x$token %in% c("SYMBOL", "SYMBOL_FUNCTION_CALL"))</pre>
+                      <pre class="language-r">    parents(x) %in% names(new_jk)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">171</td>
+                    <td class="num">111</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">172</td>
-                    <td class="coverage">128<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">      if (length(sym_cond) == 0) {</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">173</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="num">112</td>
+                    <td class="coverage">9<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        return(character(0))</pre>
+                      <pre class="language-r">  if (any(common_parents_ix)) parents(new_jk) &lt;- parents(x)[common_parents_ix]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">174</td>
+                    <td class="num">113</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      }</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">175</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">114</td>
+                    <td class="coverage">19<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      # Watch out for SYMBOLS after $ and @. For x$a x@a: x is object, a is not.</pre>
+                      <pre class="language-r">  new_jk</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">176</td>
+                    <td class="num">115</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      # For x$a, a's ID is $'s ID-2 so we need to remove all IDs that have ID = $ID - 2.</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">177</td>
-                    <td class="coverage">126<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">116</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      dollar_ids &lt;- x[x$token %in% c("'$'", "'@'"), "id"]</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">178</td>
-                    <td class="coverage">126<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">117</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      if (length(dollar_ids)) {</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">179</td>
-                    <td class="coverage">12<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">118</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        object_ids &lt;- x[sym_cond, "id"]</pre>
+                      <pre class="language-r">#' @order 2</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">180</td>
-                    <td class="coverage">12<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">119</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        after_dollar &lt;- object_ids[(object_ids - 2) %in% dollar_ids]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">181</td>
-                    <td class="coverage">12<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">120</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        sym_cond &lt;- setdiff(sym_cond, which(x$id %in% after_dollar))</pre>
+                      <pre class="language-r">#' @param directed (`logical(1)`) Flag that indicates whether it should create</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">182</td>
+                    <td class="num">121</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      }</pre>
+                      <pre class="language-r">#' a parent-child relationship between the datasets.\cr</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">183</td>
+                    <td class="num">122</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'  - `TRUE` (default) `dataset_1` is the parent of `dataset_2`;</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">184</td>
+                    <td class="num">123</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      # If there was an assignment operation detect direction of it.</pre>
+                      <pre class="language-r">#'  - `FALSE` when the relationship is undirected.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">185</td>
-                    <td class="coverage">126<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">124</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ass_cond &lt;- grep("ASSIGN", x$token)</pre>
+                      <pre class="language-r">#' @section Functions:</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">186</td>
-                    <td class="coverage">126<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">125</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      if (length(ass_cond)) { # NOTE 1</pre>
+                      <pre class="language-r">#' - `x[i, j] &lt;- value`: Assignment of a key to pair `(i, j)`.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">187</td>
-                    <td class="coverage">109<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">126</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        sym_cond &lt;- sym_cond[sym_cond &gt; ass_cond] # NOTE 2</pre>
+                      <pre class="language-r">#' - `x[i] &lt;- value`: This (without `j` parameter) **is not** a supported</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">188</td>
+                    <td class="num">127</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      }</pre>
+                      <pre class="language-r">#' operation for `join_keys`.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">189</td>
-                    <td class="coverage">126<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">128</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      if ((length(ass_cond) &amp;&amp; x$text[ass_cond] == "-&gt;") || !length(ass_cond)) { # NOTE 3</pre>
+                      <pre class="language-r">#' - `join_keys(x)[i, j] &lt;- value`: Assignment to `join_keys` object stored in `x`,</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">190</td>
-                    <td class="coverage">19<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">129</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        sym_cond &lt;- rev(sym_cond)</pre>
+                      <pre class="language-r">#' such as a `teal_data` or `join_keys` itself.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">191</td>
+                    <td class="num">130</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      }</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">192</td>
-                    <td class="coverage">126<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">131</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      append(unique(x[sym_cond, "text"]), "&lt;-", after = 1)</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">193</td>
+                    <td class="num">132</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">194</td>
+                    <td class="num">133</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ### NOTE 3: What if there are 2+ assignments, e.g. a &lt;- b -&gt; c or e.g. a &lt;- b &lt;- c.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">195</td>
+                    <td class="num">134</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ### NOTE 2: For cases like 'eval(expression(b &lt;- b + 2))' removes 'eval(expression('.</pre>
+                      <pre class="language-r">#' # Setting a new primary key ---</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">196</td>
+                    <td class="num">135</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ### NOTE 1: Cases like 'data(iris)' that do not have an assignment operator.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">197</td>
+                    <td class="num">136</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ### NOTE 1: Then they are parsed as c("iris", "&lt;-", "data")</pre>
+                      <pre class="language-r">#' jk["ds4", "ds4"] &lt;- "pk4"</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">198</td>
+                    <td class="num">137</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">#' jk["ds5", "ds5"] &lt;- "pk5"</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">199</td>
+                    <td class="num">138</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">200</td>
+                    <td class="num">139</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#' # Setting a single relationship pair ---</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">201</td>
+                    <td class="num">140</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">202</td>
+                    <td class="num">141</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Extract Side Effects</pre>
+                      <pre class="language-r">#' jk["ds1", "ds4"] &lt;- c("pk1" = "pk4")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">203</td>
+                    <td class="num">142</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">204</td>
+                    <td class="num">143</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @description Extracts all object names from the code that are marked with `@linksto` tag.</pre>
+                      <pre class="language-r">#' # Removing a key ---</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">205</td>
+                    <td class="num">144</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">206</td>
+                    <td class="num">145</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @details</pre>
+                      <pre class="language-r">#' jk["ds5", "ds5"] &lt;- NULL</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">207</td>
+                    <td class="num">146</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' The code may contain functions calls that create side effects, e.g. modify the environment.</pre>
+                      <pre class="language-r">`[&lt;-.join_keys` &lt;- function(x, i, j, directed = TRUE, value) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">208</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">147</td>
+                    <td class="coverage">11<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Static code analysis may be insufficient to determine which objects are created or modified by such a function call.</pre>
+                      <pre class="language-r">  checkmate::assert_flag(directed)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">209</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">148</td>
+                    <td class="coverage">11<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' The `@linksto` comment tag is introduced to mark a call as having a (side) effect on one or more objects.</pre>
+                      <pre class="language-r">  if (missing(i) || missing(j)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">210</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">149</td>
+                    <td class="coverage">4<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' With this tag a complete object dependency structure can be established.</pre>
+                      <pre class="language-r">    stop("join_keys[i, j] specify both indices to set a key pair.")</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">211</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">150</td>
+                    <td class="coverage">7<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Read more about side effects and the usage of `@linksto` tag in [`get_code_dependencies()`] function.</pre>
+                      <pre class="language-r">  } else if (!missing(i) &amp;&amp; is.null(i) || !missing(j) &amp;&amp; is.null(j)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">212</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">151</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    stop("join_keys[i, j] neither i nor j can be NULL.")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">213</td>
+                    <td class="num">152</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
+                      <pre class="language-r">  } else if (</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">214</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">153</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
+                      <pre class="language-r">    !any(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">215</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">154</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
+                      <pre class="language-r">      checkmate::test_string(i),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">216</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">155</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      checkmate::test_number(i),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">217</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">156</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return</pre>
+                      <pre class="language-r">      checkmate::test_logical(i, len = length(x)) &amp;&amp; sum(j) == 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">218</td>
+                    <td class="num">157</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' A list of length equal to that of `calls_pd`, where each element is a character vector of names of objects</pre>
+                      <pre class="language-r">    ) ||</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">219</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">158</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' depending a call tagged with `@linksto` in a corresponding element of `calls_pd`.</pre>
+                      <pre class="language-r">      !any(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">220</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">159</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">        checkmate::test_string(j),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">221</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">160</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">        checkmate::test_number(j),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">222</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">161</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @noRd</pre>
+                      <pre class="language-r">        checkmate::test_logical(j, len = length(x)) &amp;&amp; sum(j) == 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">223</td>
+                    <td class="num">162</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">extract_side_effects &lt;- function(calls_pd) {</pre>
+                      <pre class="language-r">      )</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">224</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">163</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  lapply(</pre>
+                      <pre class="language-r">  ) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">225</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">164</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    calls_pd,</pre>
+                      <pre class="language-r">    stop(</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">226</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">165</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    function(x) {</pre>
+                      <pre class="language-r">      "join_keys[i, j] &lt;- Can't set keys to specified indices.\n",</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">227</td>
-                    <td class="coverage">131<em>x</em></td>
+                    <td class="num">166</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      linksto &lt;- grep("@linksto", x[x$token == "COMMENT", "text"], value = TRUE)</pre>
+                      <pre class="language-r">      "When setting pair [i, j], both indices must point to a single key pair.\n",</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">228</td>
-                    <td class="coverage">131<em>x</em></td>
+                    <td class="num">167</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      unlist(strsplit(sub("\\s*#\\s*@linksto\\s+", "", linksto), "\\s+"))</pre>
+                      <pre class="language-r">      call. = FALSE</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">229</td>
+                    <td class="num">168</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">    )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">230</td>
+                    <td class="num">169</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">231</td>
+                    <td class="num">170</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">232</td>
+                    <td class="num">171</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  # Handle join key removal separately</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">172</td>
+                    <td class="coverage">3<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  if (is.null(value)) {</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">173</td>
+                    <td class="coverage">1<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">    x[[i]][[j]] &lt;- NULL</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">174</td>
+                    <td class="coverage">1<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">    return(x)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">233</td>
+                    <td class="num">175</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"># graph_parser ----</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">234</td>
+                    <td class="num">176</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r"></pre>
                     </td>
                   </tr>
+                  <tr class="covered">
+                    <td class="num">177</td>
+                    <td class="coverage">2<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  c(x, join_key(i, j, value, directed))</pre>
+                    </td>
+                  </tr>
                   <tr class="never">
-                    <td class="num">235</td>
+                    <td class="num">178</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Return the indices of calls needed to reproduce an object</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">236</td>
+                    <td class="num">179</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">237</td>
+                    <td class="num">180</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param x The name of the object to return code for.</pre>
+                      <pre class="language-r">#' @noRd</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">238</td>
+                    <td class="num">181</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param graph A result of `code_graph()`.</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">239</td>
+                    <td class="num">182</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">240</td>
+                    <td class="num">183</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return</pre>
+                      <pre class="language-r">#' @order 1000</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">241</td>
+                    <td class="num">184</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Integer vector of indices that can be applied to `graph` to obtain all calls required to reproduce object `x`.</pre>
+                      <pre class="language-r">#' @usage ## Prefered method is x[i, j] &lt;- value</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">242</td>
+                    <td class="num">185</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' x[[i]][[j]] &lt;- value</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">243</td>
+                    <td class="num">186</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">244</td>
+                    <td class="num">187</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @noRd</pre>
+                      <pre class="language-r">#' @section Functions:</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">245</td>
+                    <td class="num">188</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">graph_parser &lt;- function(x, graph) {</pre>
+                      <pre class="language-r">#' - `x[[i]][[j]] &lt;- value`: It is equivalent as  `x[i, j] &lt;- value`.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">246</td>
-                    <td class="coverage">167<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">189</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  occurrence &lt;- vapply(</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">247</td>
-                    <td class="coverage">167<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">190</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    graph, function(call) {</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">248</td>
-                    <td class="coverage">467<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">191</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ind &lt;- match("&lt;-", call, nomatch = length(call) + 1L)</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">249</td>
-                    <td class="coverage">467<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">192</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      x %in% call[seq_len(ind - 1L)]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">250</td>
+                    <td class="num">193</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    },</pre>
+                      <pre class="language-r">#' # Setting via x[[i]] &lt;- value ---</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">251</td>
-                    <td class="coverage">167<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">194</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    logical(1)</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">252</td>
+                    <td class="num">195</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">#' jk &lt;- join_keys()</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">253</td>
+                    <td class="num">196</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' jk[["ds6"]][["ds6"]] &lt;- "pk6"</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">254</td>
-                    <td class="coverage">167<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">197</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  dependencies &lt;- lapply(graph[occurrence], function(call) {</pre>
+                      <pre class="language-r">#' jk[["ds7"]] &lt;- list(ds7 = "pk7", ds6 = c(pk7 = "pk6"))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">255</td>
-                    <td class="coverage">89<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">198</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    ind &lt;- match("&lt;-", call, nomatch = 0L)</pre>
+                      <pre class="language-r">#' jk[["ds7"]][["ds7"]] &lt;- NULL # removes key</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">256</td>
-                    <td class="coverage">89<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">199</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    call[(ind + 1L):length(call)]</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">257</td>
+                    <td class="num">200</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  })</pre>
+                      <pre class="language-r">#' jk</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">201</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">`[[&lt;-.join_keys` &lt;- function(x, i, value) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">258</td>
-                    <td class="coverage">167<em>x</em></td>
+                    <td class="num">202</td>
+                    <td class="coverage">380<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  dependencies &lt;- setdiff(unlist(dependencies), x)</pre>
+                      <pre class="language-r">  checkmate::assert(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">259</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">203</td>
+                    <td class="coverage">380<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    combine = "or",</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">260</td>
-                    <td class="coverage">167<em>x</em></td>
+                    <td class="num">204</td>
+                    <td class="coverage">380<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (length(dependencies) &amp;&amp; any(occurrence)) {</pre>
+                      <pre class="language-r">    checkmate::check_string(i),</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">261</td>
-                    <td class="coverage">64<em>x</em></td>
+                    <td class="num">205</td>
+                    <td class="coverage">380<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    dependency_ids &lt;- lapply(dependencies, function(dependency) {</pre>
+                      <pre class="language-r">    checkmate::check_number(i),</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">262</td>
-                    <td class="coverage">127<em>x</em></td>
+                    <td class="num">206</td>
+                    <td class="coverage">380<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      graph_parser(dependency, graph[1:max(which(occurrence))])</pre>
+                      <pre class="language-r">    checkmate::check_logical(i, len = length(x))</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">263</td>
+                    <td class="num">207</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    })</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">264</td>
-                    <td class="coverage">64<em>x</em></td>
+                    <td class="num">208</td>
+                    <td class="coverage">380<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    sort(unique(c(which(occurrence), unlist(dependency_ids))))</pre>
+                      <pre class="language-r">  checkmate::assert_list(value, names = "named", types = "character", null.ok = TRUE)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">265</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">209</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else {</pre>
+                      <pre class="language-r">  if (checkmate::test_numeric(i) || checkmate::test_logical(i)) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">266</td>
-                    <td class="coverage">103<em>x</em></td>
+                    <td class="num">210</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    which(occurrence)</pre>
+                      <pre class="language-r">    i &lt;- names(x)[[i]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">267</td>
+                    <td class="num">211</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">268</td>
+                    <td class="num">212</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">269</td>
+                    <td class="num">213</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  # Normalize values</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">270</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">214</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  norm_value &lt;- lapply(seq_along(value), function(.x) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">271</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">215</td>
+                    <td class="coverage">522<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"># default_side_effects --------------------------------------------------------------------------------------------</pre>
+                      <pre class="language-r">    join_key(i, names(value)[.x], value[[.x]])</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">272</td>
+                    <td class="num">216</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">  })</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">273</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">217</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Detect Library Calls</pre>
+                      <pre class="language-r">  names(norm_value) &lt;- names(value)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">274</td>
+                    <td class="num">218</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">275</td>
+                    <td class="num">219</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Detects `library()` and `require()` function calls.</pre>
+                      <pre class="language-r">  # Check if multiple modifications don't have a conflict</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">276</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">220</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  repeated_value_ix &lt;- names(value) %in% names(value)[duplicated(names(value))]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">277</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">221</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param calls_pd `list` of `data.frame`s;</pre>
+                      <pre class="language-r">  repeated &lt;- norm_value[repeated_value_ix]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">278</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">222</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  result of `utils::getParseData()` split into subsets representing individual calls;</pre>
+                      <pre class="language-r">  vapply(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">279</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">223</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  created by `extract_calls()` function</pre>
+                      <pre class="language-r">    seq_along(repeated),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">280</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">224</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    function(.ix, .x_value = repeated[[.ix]], .x_name = names(.x_value[[1]])) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">281</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">225</td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return</pre>
+                      <pre class="language-r">      assert_compatible_keys2(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">282</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">226</td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Integer vector of indices that can be applied to `graph` (result of `code_graph()`) to obtain all calls containing</pre>
+                      <pre class="language-r">        .x_value,</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">283</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">227</td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' `library()` or `require()` calls that are always returned for reproducibility.</pre>
+                      <pre class="language-r">        unlist(unname(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">284</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">228</td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">          repeated[-.ix][names(repeated[-.ix]) == .x_name]</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">285</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">229</td>
+                    <td class="coverage">3<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">        ), recursive = FALSE)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">286</td>
+                    <td class="num">230</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @noRd</pre>
+                      <pre class="language-r">      )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">287</td>
+                    <td class="num">231</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">detect_libraries &lt;- function(calls_pd) {</pre>
+                      <pre class="language-r">    },</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">288</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">232</td>
+                    <td class="coverage">373<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  defaults &lt;- c("library", "require")</pre>
+                      <pre class="language-r">    logical(1)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">289</td>
+                    <td class="num">233</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  )</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">234</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">290</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">235</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  which(</pre>
+                      <pre class="language-r">  norm_value &lt;- lapply(norm_value, function(x) x[[1]][[1]])</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">291</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">236</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    vapply(</pre>
+                      <pre class="language-r">  names(norm_value) &lt;- names(value)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">292</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">237</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      calls_pd,</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">293</td>
-                    <td class="coverage">38<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">238</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      function(call) {</pre>
+                      <pre class="language-r">  # Safe to do as duplicated are the same</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">294</td>
-                    <td class="coverage">131<em>x</em></td>
+                    <td class="num">239</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        any(call$token == "SYMBOL_FUNCTION_CALL" &amp; call$text %in% defaults)</pre>
+                      <pre class="language-r">  norm_value[duplicated(names(norm_value))] &lt;- NULL</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">295</td>
+                    <td class="num">240</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      },</pre>
+                      <pre class="language-r"></pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">241</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  # Keep only elements with length &gt; 0L</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">296</td>
-                    <td class="coverage">38<em>x</em></td>
+                    <td class="num">242</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      logical(1)</pre>
+                      <pre class="language-r">  norm_value &lt;- Filter(length, norm_value)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">297</td>
+                    <td class="num">243</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    )</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">298</td>
+                    <td class="num">244</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">  # Remove classes to use list-based get/assign operations</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">299</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">245</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">  new_x &lt;- unclass(x)</pre>
                     </td>
                   </tr>
-                </tbody>
-              </table>
-            </div>
-            <div id="R/dummy_function.R" class="hidden">
-              <table class="table-condensed">
-                <tbody>
                   <tr class="never">
-                    <td class="num">1</td>
+                    <td class="num">246</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' This function returns a dummy dataset for testing examples and should only be used within `teal.data`.</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">2</td>
+                    <td class="num">247</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  # In case a pair is removed, also remove the symmetric pair and update parents</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">3</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">248</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' It is not meant to retrieve the `SCDA` dataset, and the dataset itself is not maintained here.</pre>
+                      <pre class="language-r">  removed_names &lt;- setdiff(names(new_x[[i]]), names(norm_value))</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">4</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">249</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  for (.x in removed_names) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">5</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">250</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' This function creates a copy of the `SCDA` data for testing purposes.</pre>
+                      <pre class="language-r">    if (identical(parent(x, .x), i)) attr(new_x, "parents")[[.x]] &lt;- NULL</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">6</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">251</td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    if (identical(parent(x, i), .x)) attr(new_x, "parents")[[i]] &lt;- NULL</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">7</td>
+                    <td class="num">252</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' `CDISC` data includes `ADSL`, `ADAE`, `ADLB`, `ADCM`, `ADEX`, `ADRS`, `ADTR` and `ADTTE`.</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">8</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">253</td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    new_x[[.x]][[i]] &lt;- NULL</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">9</td>
+                    <td class="num">254</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param dataname name of the `CDISC` dataset</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">10</td>
+                    <td class="num">255</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">11</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">256</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return `cdisc_data`</pre>
+                      <pre class="language-r">  new_x[[i]] &lt;- norm_value</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">12</td>
+                    <td class="num">257</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">13</td>
+                    <td class="num">258</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">  # Iterate on all new values to create symmetrical pair</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">14</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">259</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">example_cdisc_data &lt;- function(dataname) {</pre>
+                      <pre class="language-r">  for (ds2 in names(norm_value)) {</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">260</td>
+                    <td class="coverage">297<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">    if (ds2 == i) next</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">15</td>
+                    <td class="num">261</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Define the available datasets</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">16</td>
-                    <td class="coverage">!</td>
+                  <tr class="covered">
+                    <td class="num">262</td>
+                    <td class="coverage">221<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  datasets &lt;- c("ADSL", "ADAE", "ADLB", "ADCM", "ADEX", "ADRS", "ADTR", "ADTTE", "ADVS")</pre>
+                      <pre class="language-r">    keep_value &lt;- if (is.null(x)) list() else new_x[[ds2]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">17</td>
+                    <td class="num">263</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">18</td>
+                    <td class="num">264</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # Check if the provided dataname is valid</pre>
+                      <pre class="language-r">    # Invert key</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">19</td>
-                    <td class="coverage">!</td>
+                  <tr class="covered">
+                    <td class="num">265</td>
+                    <td class="coverage">221<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (dataname %in% datasets) {</pre>
+                      <pre class="language-r">    new_value &lt;- stats::setNames(names(norm_value[[ds2]]), norm_value[[ds2]])</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">20</td>
-                    <td class="coverage">!</td>
+                  <tr class="covered">
+                    <td class="num">266</td>
+                    <td class="coverage">221<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    dataset &lt;- get(paste0("r", dataname))</pre>
+                      <pre class="language-r">    keep_value[[i]] &lt;- new_value</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">21</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">267</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(dataset)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">22</td>
+                    <td class="num">268</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else {</pre>
+                      <pre class="language-r">    # Assign symmetrical</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">23</td>
-                    <td class="coverage">!</td>
+                  <tr class="covered">
+                    <td class="num">269</td>
+                    <td class="coverage">221<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    stop("Invalid dataname. Please provide one of the following: ", paste(datasets, collapse = ", "))</pre>
+                      <pre class="language-r">    new_x[[ds2]] &lt;- keep_value</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">24</td>
+                    <td class="num">270</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">25</td>
+                    <td class="num">271</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                </tbody>
-              </table>
-            </div>
-            <div id="R/teal_data-datanames.R" class="hidden">
-              <table class="table-condensed">
-                <tbody>
-                  <tr class="never">
-                    <td class="num">1</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">272</td>
+                    <td class="coverage">372<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Names of Data Sets in `teal_data` Object</pre>
+                      <pre class="language-r">  preserve_attr &lt;- attributes(new_x)[!names(attributes(new_x)) %in% "names"]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">2</td>
+                    <td class="num">273</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  # Remove NULL or empty keys</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">274</td>
+                    <td class="coverage">372<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  new_x &lt;- Filter(function(x) length(x) != 0L, new_x)</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">275</td>
+                    <td class="coverage">372<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  attributes(new_x) &lt;- utils::modifyList(attributes(new_x), preserve_attr)</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">276</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r"></pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">277</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  #</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">278</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  # restore class</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">279</td>
+                    <td class="coverage">372<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  class(new_x) &lt;- class(x)</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">280</td>
+                    <td class="coverage">372<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  new_x</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">281</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">}</pre>
+                    </td>
+                  </tr>
+                </tbody>
+              </table>
+            </div>
+            <div id="R/dummy_function.R" class="hidden">
+              <table class="table-condensed">
+                <tbody>
+                  <tr class="never">
+                    <td class="num">1</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' This function returns a dummy dataset for testing examples and should only be used within `teal.data`.</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
@@ -4874,7 +5063,7 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Get or set the value of the `datanames` slot.</pre>
+                      <pre class="language-r">#' It is not meant to retrieve the `SCDA` dataset, and the dataset itself is not maintained here.</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -4888,35 +5077,35 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' The `@datanames` slot in a `teal_data` object specifies which of the variables stored in its environment</pre>
+                      <pre class="language-r">#' This function creates a copy of the `SCDA` data for testing purposes.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' (the `@env` slot) are data sets to be taken into consideration.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' The contents of `@datanames` can be specified upon creation and default to all variables in `@env`.</pre>
+                      <pre class="language-r">#' `CDISC` data includes `ADSL`, `ADAE`, `ADLB`, `ADCM`, `ADEX`, `ADRS`, `ADTR` and `ADTTE`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Variables created later, which may well be data sets, are not automatically considered such.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Use this function to update the slot.</pre>
+                      <pre class="language-r">#' @param dataname name of the `CDISC` dataset</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -4930,245 +5119,426 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param x (`teal_data`) object to access or modify</pre>
+                      <pre class="language-r">#' @return `cdisc_data`</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">12</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param value (`character`) new value for `@datanames`; all elements must be names of variables existing in `@env`</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">13</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">14</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return The contents of `@datanames` or `teal_data` with updated `@datanames`.</pre>
+                      <pre class="language-r">example_cdisc_data &lt;- function(dataname) {</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  # Define the available datasets</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">16</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">  datasets &lt;- c("ADSL", "ADAE", "ADLB", "ADCM", "ADEX", "ADRS", "ADTR", "ADTTE", "ADVS")</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' td &lt;- teal_data(iris = iris)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">18</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' td &lt;- within(td, mtcars &lt;- mtcars)</pre>
+                      <pre class="language-r">  # Check if the provided dataname is valid</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">19</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' datanames(td)</pre>
+                      <pre class="language-r">  if (dataname %in% datasets) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">20</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' datanames(td) &lt;- c("iris", "mtcars")</pre>
+                      <pre class="language-r">    dataset &lt;- get(paste0("r", dataname))</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">21</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">    return(dataset)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">22</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @name datanames</pre>
+                      <pre class="language-r">  } else {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">23</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @aliases datanames,teal_data-method</pre>
+                      <pre class="language-r">    stop("Invalid dataname. Please provide one of the following: ", paste(datasets, collapse = ", "))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">24</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @aliases datanames&lt;-,teal_data,character-method</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">25</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @aliases datanames,qenv.error-method</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
+                </tbody>
+              </table>
+            </div>
+            <div id="R/teal_data-datanames.R" class="hidden">
+              <table class="table-condensed">
+                <tbody>
                   <tr class="never">
-                    <td class="num">26</td>
+                    <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @aliases datanames&lt;-,qenv.error,character-method</pre>
+                      <pre class="language-r">#' Names of Data Sets in `teal_data` Object</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">27</td>
+                    <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">28</td>
+                    <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname datanames</pre>
+                      <pre class="language-r">#' Get or set the value of the `datanames` slot.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">29</td>
+                    <td class="num">4</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">30</td>
-                    <td class="coverage">47<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">setGeneric("datanames", function(x) standardGeneric("datanames"))</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">31</td>
+                    <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">setMethod("datanames", signature = "teal_data", definition = function(x) {</pre>
+                      <pre class="language-r">#' The `@datanames` slot in a `teal_data` object specifies which of the variables stored in its environment</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">32</td>
-                    <td class="coverage">45<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">6</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x@datanames</pre>
+                      <pre class="language-r">#' (the `@env` slot) are data sets to be taken into consideration.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">33</td>
+                    <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">})</pre>
+                      <pre class="language-r">#' The contents of `@datanames` can be specified upon creation and default to all variables in `@env`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">34</td>
+                    <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">setMethod("datanames", signature = "qenv.error", definition = function(x) {</pre>
+                      <pre class="language-r">#' Variables created later, which may well be data sets, are not automatically considered such.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">35</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">9</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  NULL</pre>
+                      <pre class="language-r">#' Use this function to update the slot.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">36</td>
+                    <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">})</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">37</td>
+                    <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @param x (`teal_data`) object to access or modify</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">38</td>
+                    <td class="num">12</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname datanames</pre>
+                      <pre class="language-r">#' @param value (`character`) new value for `@datanames`; all elements must be names of variables existing in `@env`</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">39</td>
+                    <td class="num">13</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">40</td>
-                    <td class="coverage">32<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">14</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">setGeneric("datanames&lt;-", function(x, value) standardGeneric("datanames&lt;-"))</pre>
+                      <pre class="language-r">#' @return The contents of `@datanames` or `teal_data` with updated `@datanames`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">41</td>
+                    <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">setMethod("datanames&lt;-", signature = c("teal_data", "character"), definition = function(x, value) {</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">42</td>
-                    <td class="coverage">31<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">16</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_subset(value, names(x@env))</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">43</td>
-                    <td class="coverage">30<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">17</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x@datanames &lt;- value</pre>
+                      <pre class="language-r">#' td &lt;- teal_data(iris = iris)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">44</td>
-                    <td class="coverage">30<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">18</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  methods::validObject(x)</pre>
+                      <pre class="language-r">#' td &lt;- within(td, mtcars &lt;- mtcars)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">45</td>
-                    <td class="coverage">30<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">19</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x</pre>
+                      <pre class="language-r">#' datanames(td)</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">20</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' datanames(td) &lt;- c("iris", "mtcars")</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">21</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#'</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">22</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @name datanames</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">23</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @aliases datanames,teal_data-method</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">24</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @aliases datanames&lt;-,teal_data,character-method</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">25</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @aliases datanames,qenv.error-method</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">26</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @aliases datanames&lt;-,qenv.error,character-method</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">27</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r"></pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">28</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @rdname datanames</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">29</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @export</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">30</td>
+                    <td class="coverage">49<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">setGeneric("datanames", function(x) standardGeneric("datanames"))</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">31</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">setMethod("datanames", signature = "teal_data", definition = function(x) {</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">32</td>
+                    <td class="coverage">47<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  x@datanames</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">33</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">})</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">34</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">setMethod("datanames", signature = "qenv.error", definition = function(x) {</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">35</td>
+                    <td class="coverage">2<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  NULL</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">36</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">})</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">37</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r"></pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">38</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @rdname datanames</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">39</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">#' @export</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">40</td>
+                    <td class="coverage">33<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">setGeneric("datanames&lt;-", function(x, value) standardGeneric("datanames&lt;-"))</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">41</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">setMethod("datanames&lt;-", signature = c("teal_data", "character"), definition = function(x, value) {</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">42</td>
+                    <td class="coverage">32<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  checkmate::assert_subset(value, names(x@env))</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">43</td>
+                    <td class="coverage">31<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  x@datanames &lt;- value</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">44</td>
+                    <td class="coverage">31<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  methods::validObject(x)</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">45</td>
+                    <td class="coverage">31<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  x</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -9679,293 +10049,147 @@ <h2>teal.data coverage - 78.35%</h2>
                 </tbody>
               </table>
             </div>
-            <div id="R/zzz.R" class="hidden">
+            <div id="R/teal_data-get_code.R" class="hidden">
               <table class="table-condensed">
                 <tbody>
                   <tr class="never">
                     <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">.onLoad &lt;- function(libname, pkgname) { # nolint</pre>
+                      <pre class="language-r">#' Get Code from `teal_data`</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # expose default CDISC dataset names</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # copy from excel file</pre>
+                      <pre class="language-r">#' Retrieve code from `teal_data` object.</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">4</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  default_cdisc_keys &lt;- yaml::yaml.load_file(</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">5</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    system.file("cdisc_datasets/cdisc_datasets.yaml", package = "teal.data")</pre>
+                      <pre class="language-r">#' Retrieve code stored in `@code`, which (in principle) can be used to recreate all objects found in `@env`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">#' Use `datanames` to limit the code to one or more of the data sets enumerated in `@datanames`.</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">7</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  assign("default_cdisc_keys", default_cdisc_keys, envir = parent.env(environment()))</pre>
+                      <pre class="language-r">#' If the code has not passed verification (with [`verify()`]), a warning will be prepended.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  # update default_cdisc_join_keys</pre>
+                      <pre class="language-r">#' @section Notes for Developers:</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">10</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  assign(</pre>
+                      <pre class="language-r">#' To learn more about how a subset of code needed to reproduce a specific data set is extracted from all code,</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">11</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    "default_cdisc_join_keys",</pre>
+                      <pre class="language-r">#' see [`get_code_dependency()`].</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">12</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    build_cdisc_join_keys(default_cdisc_keys),</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">13</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    envir = parent.env(environment())</pre>
+                      <pre class="language-r">#' @param object (`teal_data`)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">14</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">#' @param datanames `r lifecycle::badge("experimental")` (`character`) vector of data set names to return the code for.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @param deparse (`logical`) flag specifying whether to return code as `character` (`deparse = TRUE`) or as</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">16</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  invisible()</pre>
+                      <pre class="language-r">#' `expression` (`deparse = FALSE`).</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#' @return</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">18</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' Either string or an expression representing code used to create the requested data sets.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">19</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"># use non-exported function from teal.code</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">20</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">lang2calls &lt;- getFromNamespace("lang2calls", "teal.code")</pre>
-                    </td>
-                  </tr>
-                </tbody>
-              </table>
-            </div>
-            <div id="R/teal_data-get_code.R" class="hidden">
-              <table class="table-condensed">
-                <tbody>
-                  <tr class="never">
-                    <td class="num">1</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' Get Code from `teal_data`</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">2</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">3</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' Retrieve code from `teal_data` object.</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">4</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">5</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' Retrieve code stored in `@code`, which (in principle) can be used to recreate all objects found in `@env`.</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">6</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' Use `datanames` to limit the code to one or more of the data sets enumerated in `@datanames`.</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">7</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' If the code has not passed verification (with [`verify()`]), a warning will be prepended.</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">8</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">9</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @section Notes for Developers:</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">10</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' To learn more about how a subset of code needed to reproduce a specific data set is extracted from all code,</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">11</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' see [`get_code_dependency()`].</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">12</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">13</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @param object (`teal_data`)</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">14</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @param datanames `r lifecycle::badge("experimental")` (`character`) vector of data set names to return the code for.</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">15</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @param deparse (`logical`) flag specifying whether to return code as `character` (`deparse = TRUE`) or as</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">16</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' `expression` (`deparse = FALSE`).</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">17</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @return</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">18</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' Either string or an expression representing code used to create the requested data sets.</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">19</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">20</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -10096,21 +10320,21 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">39</td>
-                    <td class="coverage">45<em>x</em></td>
+                    <td class="coverage">47<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  checkmate::assert_character(datanames, min.len = 1L, null.ok = TRUE)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">40</td>
-                    <td class="coverage">45<em>x</em></td>
+                    <td class="coverage">47<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  checkmate::assert_subset(datanames, datanames(object))</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">41</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">46<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  checkmate::assert_flag(deparse)</pre>
                     </td>
@@ -10124,14 +10348,14 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">43</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">46<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  code &lt;- if (!is.null(datanames)) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">44</td>
-                    <td class="coverage">40<em>x</em></td>
+                    <td class="coverage">42<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    get_code_dependency(object@code, datanames)</pre>
                     </td>
@@ -10166,7 +10390,7 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">49</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">46<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  if (!object@verified) {</pre>
                     </td>
@@ -10194,14 +10418,14 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">53</td>
-                    <td class="coverage">44<em>x</em></td>
+                    <td class="coverage">46<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  if (deparse) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">54</td>
-                    <td class="coverage">43<em>x</em></td>
+                    <td class="coverage">45<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    if (length(code) == 0) {</pre>
                     </td>
@@ -10222,7 +10446,7 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">57</td>
-                    <td class="coverage">43<em>x</em></td>
+                    <td class="coverage">45<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">      paste(code, collapse = "\n")</pre>
                     </td>
@@ -10473,14 +10697,14 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">30</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  data_objects &lt;- rlang::list2(...)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">31</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  if (inherits(join_keys, "join_key_set")) {</pre>
                     </td>
@@ -10508,28 +10732,28 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">35</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    checkmate::test_list(</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">36</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">      data_objects,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">37</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">      types = c("TealDataConnector", "TealDataset", "TealDatasetConnector"),</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">38</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">      min.len = 1</pre>
                     </td>
@@ -10606,7 +10830,7 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">49</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    if (length(data_objects) &gt; 0 &amp;&amp; !checkmate::test_names(names(data_objects), type = "named")) {</pre>
                     </td>
@@ -10627,28 +10851,28 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">52</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    new_teal_data(</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">53</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">      data = data_objects,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">54</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">      code = code,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">55</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">      join_keys = join_keys</pre>
                     </td>
@@ -10677,28 +10901,28 @@ <h2>teal.data coverage - 78.35%</h2>
                 </tbody>
               </table>
             </div>
-            <div id="R/join_keys.R" class="hidden">
+            <div id="R/verify.R" class="hidden">
               <table class="table-condensed">
                 <tbody>
                   <tr class="never">
                     <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Manage relationships between datasets using `join_keys`</pre>
+                      <pre class="language-r">#' Verify Code Reproducibility</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 1</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @name join_keys</pre>
+                      <pre class="language-r">#' Checks whether code in `teal_data` reproduces the stored objects.</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -10712,203 +10936,203 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @usage ## Constructor, getter and setter</pre>
+                      <pre class="language-r">#' If objects created by code in the `@code` slot of `x` are `all_equal` to the contents of the `@env` slot,</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(...)</pre>
+                      <pre class="language-r">#' the function updates the `@verified` slot to `TRUE` in the returned `teal_data` object. Once verified, the slot</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' will always be set to `TRUE`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @description</pre>
+                      <pre class="language-r">#' If the `@code` fails to recreate objects in `teal_data@env`, an error is raised.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Facilitates the creation and retrieval of relationships between datasets.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' `join_keys` class extends `list` and contains keys connecting pairs of datasets.</pre>
+                      <pre class="language-r">#' @return Input `teal_data` object or error.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Each element of the list contains keys for specific dataset.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">12</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Each dataset can have a relationship with itself (primary key) and with other datasets.</pre>
+                      <pre class="language-r">#' @param x `teal_data` object</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">13</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">14</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Note that `join_keys` list is symmetrical and assumes a default direction, that is:</pre>
+                      <pre class="language-r">#' tdata1 &lt;- teal_data()</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' when keys are set between `ds1` and `ds2`, it defines `ds1` as the parent</pre>
+                      <pre class="language-r">#' tdata1 &lt;- within(tdata1, {</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">16</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' in a parent-child relationship and the mapping is automatically mirrored between</pre>
+                      <pre class="language-r">#'   a &lt;- 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' `ds2` and `ds1`.</pre>
+                      <pre class="language-r">#'   b &lt;- a^5</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">18</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#'   c &lt;- list(x = 2)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">19</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @section Methods (by class):</pre>
+                      <pre class="language-r">#' })</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">20</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `join_keys()`: Returns an empty `join_keys` object when called without arguments.</pre>
+                      <pre class="language-r">#' verify(tdata1)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">21</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `join_keys(join_keys)`: Returns itself.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">22</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `join_keys(teal_data)`: Returns the `join_keys` object contained in `teal_data`.</pre>
+                      <pre class="language-r">#' tdata2 &lt;- teal_data(x1 = iris, code = "x1 &lt;- iris")</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">23</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `join_keys(...)`: Creates a new object with one or more `join_key_set` parameters.</pre>
+                      <pre class="language-r">#' verify(tdata2)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">24</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' verify(tdata2)@verified</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">25</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param ... (optional)\cr</pre>
+                      <pre class="language-r">#' tdata2@verified</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">26</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  either `teal_data` or `join_keys` to extract `join_keys`, \cr</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">27</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  or any number of `join_key_set` objects to create `join_keys`, \cr</pre>
+                      <pre class="language-r">#' \dontrun{</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">28</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'  or nothing to create an empty `join_keys`</pre>
+                      <pre class="language-r">#' tdata3 &lt;- teal_data()</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">29</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param value For `x[i, j, directed = TRUE)] &lt;- value` (named/unnamed `character`)</pre>
+                      <pre class="language-r">#' tdata3 &lt;- within(tdata3, {</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">30</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Column mapping between datasets.</pre>
+                      <pre class="language-r">#'   stop("error")</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">31</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' })</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">32</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' For `join_keys(x) &lt;- value`: (`join_key_set` or list of `join_key_set`) relationship</pre>
+                      <pre class="language-r">#' verify(tdata3)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">33</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' pairs to add to `join_keys` list.</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -10922,1707 +11146,1707 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">35</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' a &lt;- 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">36</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return `join_keys` object.</pre>
+                      <pre class="language-r">#' b &lt;- a + 2</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">37</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' c &lt;- list(x = 2)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">38</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">#' d &lt;- 5</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">39</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' tdata4 &lt;- teal_data(</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">40</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @seealso [join_key()] for creating `join_keys_set`,</pre>
+                      <pre class="language-r">#'   a = a, b = b, c = c, d = d,</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">41</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' [parents()] for parent operations,</pre>
+                      <pre class="language-r">#'   code =</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">42</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' [teal_data()] for `teal_data` constructor _and_</pre>
+                      <pre class="language-r">#'     "</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">43</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' [default_cdisc_join_keys] for default `CDISC` keys.</pre>
+                      <pre class="language-r">#'     a &lt;- 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">44</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#'     b &lt;- a</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">45</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">#'     c &lt;- list(x = 2)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">46</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Creating a new join keys ----</pre>
+                      <pre class="language-r">#'     e &lt;- 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">47</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#'     "</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">48</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk &lt;- join_keys(</pre>
+                      <pre class="language-r">#' )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">49</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   join_key("ds1", "ds1", "pk1"),</pre>
+                      <pre class="language-r">#' tdata4</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">50</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   join_key("ds2", "ds2", "pk2"),</pre>
+                      <pre class="language-r">#' verify(tdata4)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">51</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   join_key("ds3", "ds3", "pk3"),</pre>
+                      <pre class="language-r">#' }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">52</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   join_key("ds1", "ds2", c(pk1 = "pk2")),</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">53</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   join_key("ds1", "ds3", c(pk1 = "pk3"))</pre>
+                      <pre class="language-r">#' @name verify</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">54</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' )</pre>
+                      <pre class="language-r">#' @rdname verify</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">55</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @aliases verify,teal_data-method</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">56</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' jk</pre>
+                      <pre class="language-r">#' @aliases verify,qenv.error-method</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">57</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">join_keys &lt;- function(...) {</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">58</td>
-                    <td class="coverage">781<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (missing(...)) {</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">59</td>
-                    <td class="coverage">222<em>x</em></td>
+                    <td class="coverage">5<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(new_join_keys())</pre>
+                      <pre class="language-r">setGeneric("verify", function(x) standardGeneric("verify"))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">60</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">setMethod("verify", signature = "teal_data", definition = function(x) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">61</td>
-                    <td class="coverage">559<em>x</em></td>
+                    <td class="coverage">4<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x &lt;- rlang::list2(...)</pre>
+                      <pre class="language-r">  if (x@verified) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">62</td>
-                    <td class="coverage">559<em>x</em></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (length(x) == 1L) {</pre>
+                      <pre class="language-r">    return(x)</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">63</td>
-                    <td class="coverage">494<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    UseMethod("join_keys", x[[1]])</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">64</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else {</pre>
+                      <pre class="language-r">  x_name &lt;- deparse(substitute(x))</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">65</td>
-                    <td class="coverage">65<em>x</em></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    join_keys.default(...)</pre>
+                      <pre class="language-r">  y &lt;- eval_code(teal_data(), get_code(x))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">66</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">67</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">  if (inherits(y, "qenv.error")) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">68</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    stop(conditionMessage(y), call. = FALSE)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">69</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">70</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 1</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">71</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">  reproduced &lt;- isTRUE(all.equal(x@env, y@env))</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">72</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">join_keys.default &lt;- function(...) {</pre>
+                      <pre class="language-r">  if (reproduced) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">73</td>
-                    <td class="coverage">109<em>x</em></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  c(new_join_keys(), ...)</pre>
+                      <pre class="language-r">    x@verified &lt;- TRUE</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">74</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">    methods::validObject(x)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">75</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">    x</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">76</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">  } else {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">77</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 1</pre>
+                      <pre class="language-r">    error &lt;- "Code verification failed."</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">78</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">79</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">join_keys.join_keys &lt;- function(...) {</pre>
+                      <pre class="language-r">    objects_diff &lt;- vapply(</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">80</td>
-                    <td class="coverage">447<em>x</em></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x &lt;- rlang::list2(...)</pre>
+                      <pre class="language-r">      intersect(names(x@env), names(y@env)),</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">81</td>
-                    <td class="coverage">447<em>x</em></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x[[1]]</pre>
+                      <pre class="language-r">      function(element) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">82</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">        isTRUE(all.equal(x@env[[element]], y@env[[element]]))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">83</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">      },</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">84</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">      logical(1)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">85</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 1</pre>
+                      <pre class="language-r">    )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">86</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">87</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">join_keys.teal_data &lt;- function(...) {</pre>
+                      <pre class="language-r">    names_diff_other &lt;- setdiff(names(y@env), names(x@env))</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">88</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x &lt;- rlang::list2(...)</pre>
+                      <pre class="language-r">    names_diff_inenv &lt;- setdiff(names(x@env), names(y@env))</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="never">
                     <td class="num">89</td>
-                    <td class="coverage">3<em>x</em></td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x[[1]]@join_keys</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">90</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">    if (length(objects_diff)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">91</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">      error &lt;- c(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">92</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">        error,</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">93</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 5</pre>
+                      <pre class="language-r">        paste0("Object(s) recreated with code that have different structure in ", x_name, ":"),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">94</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">        paste0("  \u2022 ", names(which(!objects_diff)))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">95</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @section Functions:</pre>
+                      <pre class="language-r">      )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">96</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' - `join_keys(x) &lt;- value`: Assignment of the `join_keys` in object with `value`.</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">97</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' `value` needs to be an object of class `join_keys` or `join_key_set`.</pre>
+                      <pre class="language-r">    if (length(names_diff_inenv)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">98</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      error &lt;- c(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">99</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param x (`join_keys`) empty object to set the new relationship pairs.</pre>
+                      <pre class="language-r">        error,</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">100</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' `x` is typically an object of `join_keys` class. When called with the `join_keys(x)`</pre>
+                      <pre class="language-r">        paste0("Object(s) not created with code that exist in ", x_name, ":"),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">101</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' or `join_keys(x) &lt;- value` then it can also take a supported class (`teal_data`, `join_keys`)</pre>
+                      <pre class="language-r">        paste0("  \u2022 ", names_diff_inenv)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">102</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">      )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">103</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">104</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">`join_keys&lt;-` &lt;- function(x, value) {</pre>
+                      <pre class="language-r">    if (length(names_diff_other)) {</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="missed">
                     <td class="num">105</td>
-                    <td class="coverage">8<em>x</em></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_class(value, classes = c("join_keys", "list"))</pre>
+                      <pre class="language-r">      error &lt;- c(</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="missed">
                     <td class="num">106</td>
-                    <td class="coverage">8<em>x</em></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  UseMethod("join_keys&lt;-", x)</pre>
+                      <pre class="language-r">        error,</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">107</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">        paste0("Object(s) created with code that do not exist in ", x_name, ":"),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">108</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">        paste0("  \u2022 ", names_diff_other)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">109</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">      )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">110</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 5</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">111</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">112</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">    stop(paste(error, collapse = "\n"), call. = FALSE)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">113</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">114</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Assigning keys via join_keys(x)[i, j] &lt;- value ----</pre>
+                      <pre class="language-r">})</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">115</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">setMethod("verify", signature = "qenv.error", definition = function(x) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="covered">
                     <td class="num">116</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">1<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' obj &lt;- join_keys()</pre>
+                      <pre class="language-r">  stop(conditionMessage(x), call. = FALSE)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">117</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # or</pre>
+                      <pre class="language-r">})</pre>
                     </td>
                   </tr>
+                </tbody>
+              </table>
+            </div>
+            <div id="R/join_keys.R" class="hidden">
+              <table class="table-condensed">
+                <tbody>
                   <tr class="never">
-                    <td class="num">118</td>
+                    <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' obj &lt;- teal_data()</pre>
+                      <pre class="language-r">#' Manage relationships between datasets using `join_keys`</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">119</td>
+                    <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @order 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">120</td>
+                    <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(obj)["ds1", "ds1"] &lt;- "pk1"</pre>
+                      <pre class="language-r">#' @name join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">121</td>
+                    <td class="num">4</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(obj)["ds2", "ds2"] &lt;- "pk2"</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">122</td>
+                    <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(obj)["ds3", "ds3"] &lt;- "pk3"</pre>
+                      <pre class="language-r">#' @usage ## Constructor, getter and setter</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">123</td>
+                    <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(obj)["ds1", "ds2"] &lt;- c(pk1 = "pk2")</pre>
+                      <pre class="language-r">#' join_keys(...)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">124</td>
+                    <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(obj)["ds1", "ds3"] &lt;- c(pk1 = "pk3")</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">125</td>
+                    <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @description</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">126</td>
+                    <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' identical(jk, join_keys(obj))</pre>
+                      <pre class="language-r">#' Facilitates the creation and retrieval of relationships between datasets.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">127</td>
+                    <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">`join_keys&lt;-.join_keys` &lt;- function(x, value) {</pre>
+                      <pre class="language-r">#' `join_keys` class extends `list` and contains keys connecting pairs of datasets.</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">128</td>
-                    <td class="coverage">6<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">11</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  value</pre>
+                      <pre class="language-r">#' Each element of the list contains keys for specific dataset.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">129</td>
+                    <td class="num">12</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#' Each dataset can have a relationship with itself (primary key) and with other datasets.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">130</td>
+                    <td class="num">13</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">131</td>
+                    <td class="num">14</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname join_keys</pre>
+                      <pre class="language-r">#' Note that `join_keys` list is symmetrical and assumes a default direction, that is:</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">132</td>
+                    <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @order 5</pre>
+                      <pre class="language-r">#' when keys are set between `ds1` and `ds2`, it defines `ds1` as the parent</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">133</td>
+                    <td class="num">16</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">#' in a parent-child relationship and the mapping is automatically mirrored between</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">134</td>
+                    <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">#' `ds2` and `ds1`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">135</td>
+                    <td class="num">18</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">136</td>
+                    <td class="num">19</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # Setter for join_keys within teal_data ----</pre>
+                      <pre class="language-r">#' @section Methods (by class):</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">137</td>
+                    <td class="num">20</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' - `join_keys()`: Returns an empty `join_keys` object when called without arguments.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">138</td>
+                    <td class="num">21</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' td &lt;- teal_data()</pre>
+                      <pre class="language-r">#' - `join_keys(join_keys)`: Returns itself.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">139</td>
+                    <td class="num">22</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(td) &lt;- jk</pre>
+                      <pre class="language-r">#' - `join_keys(teal_data)`: Returns the `join_keys` object contained in `teal_data`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">140</td>
+                    <td class="num">23</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' - `join_keys(...)`: Creates a new object with one or more `join_key_set` parameters.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">141</td>
+                    <td class="num">24</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(td)["ds1", "ds2"] &lt;- "new_key"</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">142</td>
+                    <td class="num">25</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(td) &lt;- c(join_keys(td), join_keys(join_key("ds3", "ds2", "key3")))</pre>
+                      <pre class="language-r">#' @param ... (optional)\cr</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">143</td>
+                    <td class="num">26</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' join_keys(td)</pre>
+                      <pre class="language-r">#'  either `teal_data` or `join_keys` to extract `join_keys`, \cr</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">144</td>
+                    <td class="num">27</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">`join_keys&lt;-.teal_data` &lt;- function(x, value) {</pre>
+                      <pre class="language-r">#'  or any number of `join_key_set` objects to create `join_keys`, \cr</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">145</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">28</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  join_keys(x@join_keys) &lt;- value</pre>
+                      <pre class="language-r">#'  or nothing to create an empty `join_keys`</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">146</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">29</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x</pre>
+                      <pre class="language-r">#' @param value For `x[i, j, directed = TRUE)] &lt;- value` (named/unnamed `character`)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">147</td>
+                    <td class="num">30</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#' Column mapping between datasets.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">148</td>
+                    <td class="num">31</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">149</td>
+                    <td class="num">32</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Internal constructor</pre>
+                      <pre class="language-r">#' For `join_keys(x) &lt;- value`: (`join_key_set` or list of `join_key_set`) relationship</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">150</td>
+                    <td class="num">33</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' pairs to add to `join_keys` list.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">151</td>
+                    <td class="num">34</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return an empty `join_keys` list</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">152</td>
+                    <td class="num">35</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">153</td>
+                    <td class="num">36</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">#' @return `join_keys` object.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">154</td>
+                    <td class="num">37</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">new_join_keys &lt;- function() {</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">155</td>
-                    <td class="coverage">350<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">38</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  structure(</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">156</td>
-                    <td class="coverage">350<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">39</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    list(),</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">157</td>
-                    <td class="coverage">350<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">40</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    class = c("join_keys", "list"),</pre>
+                      <pre class="language-r">#' @seealso [join_key()] for creating `join_keys_set`,</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">158</td>
-                    <td class="coverage">350<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">41</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    "parents" = list()</pre>
+                      <pre class="language-r">#' [parents()] for parent operations,</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">159</td>
+                    <td class="num">42</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  )</pre>
+                      <pre class="language-r">#' [teal_data()] for `teal_data` constructor _and_</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">160</td>
+                    <td class="num">43</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">#' [default_cdisc_join_keys] for default `CDISC` keys.</pre>
                     </td>
                   </tr>
-                </tbody>
-              </table>
-            </div>
-            <div id="R/verify.R" class="hidden">
-              <table class="table-condensed">
-                <tbody>
                   <tr class="never">
-                    <td class="num">1</td>
+                    <td class="num">44</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Verify Code Reproducibility</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">2</td>
+                    <td class="num">45</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">3</td>
+                    <td class="num">46</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Checks whether code in `teal_data` reproduces the stored objects.</pre>
+                      <pre class="language-r">#' # Creating a new join keys ----</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">4</td>
+                    <td class="num">47</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">5</td>
+                    <td class="num">48</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' If objects created by code in the `@code` slot of `x` are `all_equal` to the contents of the `@env` slot,</pre>
+                      <pre class="language-r">#' jk &lt;- join_keys(</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">6</td>
+                    <td class="num">49</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' the function updates the `@verified` slot to `TRUE` in the returned `teal_data` object. Once verified, the slot</pre>
+                      <pre class="language-r">#'   join_key("ds1", "ds1", "pk1"),</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">7</td>
+                    <td class="num">50</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' will always be set to `TRUE`.</pre>
+                      <pre class="language-r">#'   join_key("ds2", "ds2", "pk2"),</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">8</td>
+                    <td class="num">51</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' If the `@code` fails to recreate objects in `teal_data@env`, an error is raised.</pre>
+                      <pre class="language-r">#'   join_key("ds3", "ds3", "pk3"),</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">9</td>
+                    <td class="num">52</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#'   join_key("ds1", "ds2", c(pk1 = "pk2")),</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">10</td>
+                    <td class="num">53</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return Input `teal_data` object or error.</pre>
+                      <pre class="language-r">#'   join_key("ds1", "ds3", c(pk1 = "pk3"))</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">11</td>
+                    <td class="num">54</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">12</td>
+                    <td class="num">55</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param x `teal_data` object</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">13</td>
+                    <td class="num">56</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">#' jk</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">14</td>
+                    <td class="num">57</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata1 &lt;- teal_data()</pre>
+                      <pre class="language-r">join_keys &lt;- function(...) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">15</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">58</td>
+                    <td class="coverage">782<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata1 &lt;- within(tdata1, {</pre>
+                      <pre class="language-r">  if (missing(...)) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">16</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">59</td>
+                    <td class="coverage">223<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   a &lt;- 1</pre>
+                      <pre class="language-r">    return(new_join_keys())</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">17</td>
+                    <td class="num">60</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   b &lt;- a^5</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">18</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">61</td>
+                    <td class="coverage">559<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   c &lt;- list(x = 2)</pre>
+                      <pre class="language-r">  x &lt;- rlang::list2(...)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">19</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">62</td>
+                    <td class="coverage">559<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' })</pre>
+                      <pre class="language-r">  if (length(x) == 1L) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">20</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">63</td>
+                    <td class="coverage">494<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' verify(tdata1)</pre>
+                      <pre class="language-r">    UseMethod("join_keys", x[[1]])</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">21</td>
+                    <td class="num">64</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  } else {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">22</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">65</td>
+                    <td class="coverage">65<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata2 &lt;- teal_data(x1 = iris, code = "x1 &lt;- iris")</pre>
+                      <pre class="language-r">    join_keys.default(...)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">23</td>
+                    <td class="num">66</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' verify(tdata2)</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">24</td>
+                    <td class="num">67</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' verify(tdata2)@verified</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">25</td>
+                    <td class="num">68</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata2@verified</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">26</td>
+                    <td class="num">69</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">27</td>
+                    <td class="num">70</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' \dontrun{</pre>
+                      <pre class="language-r">#' @order 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">28</td>
+                    <td class="num">71</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata3 &lt;- teal_data()</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">29</td>
+                    <td class="num">72</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata3 &lt;- within(tdata3, {</pre>
+                      <pre class="language-r">join_keys.default &lt;- function(...) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">30</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">73</td>
+                    <td class="coverage">109<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   stop("error")</pre>
+                      <pre class="language-r">  c(new_join_keys(), ...)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">31</td>
+                    <td class="num">74</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' })</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">32</td>
+                    <td class="num">75</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' verify(tdata3)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">33</td>
+                    <td class="num">76</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">34</td>
+                    <td class="num">77</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @order 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">35</td>
+                    <td class="num">78</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' a &lt;- 1</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">36</td>
+                    <td class="num">79</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' b &lt;- a + 2</pre>
+                      <pre class="language-r">join_keys.join_keys &lt;- function(...) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">37</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">80</td>
+                    <td class="coverage">447<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' c &lt;- list(x = 2)</pre>
+                      <pre class="language-r">  x &lt;- rlang::list2(...)</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">38</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">81</td>
+                    <td class="coverage">447<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' d &lt;- 5</pre>
+                      <pre class="language-r">  x[[1]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">39</td>
+                    <td class="num">82</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata4 &lt;- teal_data(</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">40</td>
+                    <td class="num">83</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   a = a, b = b, c = c, d = d,</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">41</td>
+                    <td class="num">84</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'   code =</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">42</td>
+                    <td class="num">85</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'     "</pre>
+                      <pre class="language-r">#' @order 1</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">43</td>
+                    <td class="num">86</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'     a &lt;- 1</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">44</td>
+                    <td class="num">87</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'     b &lt;- a</pre>
+                      <pre class="language-r">join_keys.teal_data &lt;- function(...) {</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">88</td>
+                    <td class="coverage">3<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  x &lt;- rlang::list2(...)</pre>
+                    </td>
+                  </tr>
+                  <tr class="covered">
+                    <td class="num">89</td>
+                    <td class="coverage">3<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  x[[1]]@join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">45</td>
+                    <td class="num">90</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'     c &lt;- list(x = 2)</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">46</td>
+                    <td class="num">91</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'     e &lt;- 1</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">47</td>
+                    <td class="num">92</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'     "</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">48</td>
+                    <td class="num">93</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' )</pre>
+                      <pre class="language-r">#' @order 5</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">49</td>
+                    <td class="num">94</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' tdata4</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">50</td>
+                    <td class="num">95</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' verify(tdata4)</pre>
+                      <pre class="language-r">#' @section Functions:</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">51</td>
+                    <td class="num">96</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' }</pre>
+                      <pre class="language-r">#' - `join_keys(x) &lt;- value`: Assignment of the `join_keys` in object with `value`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">52</td>
+                    <td class="num">97</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' `value` needs to be an object of class `join_keys` or `join_key_set`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">53</td>
+                    <td class="num">98</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @name verify</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">54</td>
+                    <td class="num">99</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @rdname verify</pre>
+                      <pre class="language-r">#' @param x (`join_keys`) empty object to set the new relationship pairs.</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">55</td>
+                    <td class="num">100</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @aliases verify,teal_data-method</pre>
+                      <pre class="language-r">#' `x` is typically an object of `join_keys` class. When called with the `join_keys(x)`</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">56</td>
+                    <td class="num">101</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @aliases verify,qenv.error-method</pre>
+                      <pre class="language-r">#' or `join_keys(x) &lt;- value` then it can also take a supported class (`teal_data`, `join_keys`)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">57</td>
+                    <td class="num">102</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">58</td>
+                    <td class="num">103</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">59</td>
-                    <td class="coverage">5<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">setGeneric("verify", function(x) standardGeneric("verify"))</pre>
-                    </td>
-                  </tr>
                   <tr class="never">
-                    <td class="num">60</td>
+                    <td class="num">104</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">setMethod("verify", signature = "teal_data", definition = function(x) {</pre>
+                      <pre class="language-r">`join_keys&lt;-` &lt;- function(x, value) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">61</td>
-                    <td class="coverage">4<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">  if (x@verified) {</pre>
+                    <td class="num">105</td>
+                    <td class="coverage">8<em>x</em></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">  checkmate::assert_class(value, classes = c("join_keys", "list"))</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">62</td>
-                    <td class="coverage">2<em>x</em></td>
+                    <td class="num">106</td>
+                    <td class="coverage">8<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    return(x)</pre>
+                      <pre class="language-r">  UseMethod("join_keys&lt;-", x)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">63</td>
+                    <td class="num">107</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">64</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">108</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  x_name &lt;- deparse(substitute(x))</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">65</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">109</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  y &lt;- eval_code(teal_data(), get_code(x))</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">66</td>
+                    <td class="num">110</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @order 5</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">67</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">111</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (inherits(y, "qenv.error")) {</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">68</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">112</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    stop(conditionMessage(y), call. = FALSE)</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">69</td>
+                    <td class="num">113</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">70</td>
+                    <td class="num">114</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' # Assigning keys via join_keys(x)[i, j] &lt;- value ----</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">71</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">115</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  reproduced &lt;- isTRUE(all.equal(x@env, y@env))</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">72</td>
-                    <td class="coverage">2<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">116</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (reproduced) {</pre>
+                      <pre class="language-r">#' obj &lt;- join_keys()</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">73</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">117</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    x@verified &lt;- TRUE</pre>
+                      <pre class="language-r">#' # or</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">74</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">118</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    methods::validObject(x)</pre>
+                      <pre class="language-r">#' obj &lt;- teal_data()</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">75</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">119</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    x</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">76</td>
+                    <td class="num">120</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else {</pre>
+                      <pre class="language-r">#' join_keys(obj)["ds1", "ds1"] &lt;- "pk1"</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">77</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">121</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    error &lt;- "Code verification failed."</pre>
+                      <pre class="language-r">#' join_keys(obj)["ds2", "ds2"] &lt;- "pk2"</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">78</td>
+                    <td class="num">122</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' join_keys(obj)["ds3", "ds3"] &lt;- "pk3"</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">79</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">123</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    objects_diff &lt;- vapply(</pre>
+                      <pre class="language-r">#' join_keys(obj)["ds1", "ds2"] &lt;- c(pk1 = "pk2")</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">80</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">124</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      intersect(names(x@env), names(y@env)),</pre>
+                      <pre class="language-r">#' join_keys(obj)["ds1", "ds3"] &lt;- c(pk1 = "pk3")</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">81</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">125</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      function(element) {</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">82</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">126</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        isTRUE(all.equal(x@env[[element]], y@env[[element]]))</pre>
+                      <pre class="language-r">#' identical(jk, join_keys(obj))</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">83</td>
+                    <td class="num">127</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      },</pre>
+                      <pre class="language-r">`join_keys&lt;-.join_keys` &lt;- function(x, value) {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">84</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="num">128</td>
+                    <td class="coverage">6<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      logical(1)</pre>
+                      <pre class="language-r">  value</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">85</td>
+                    <td class="num">129</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    )</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">86</td>
+                    <td class="num">130</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">87</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">131</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    names_diff_other &lt;- setdiff(names(y@env), names(x@env))</pre>
+                      <pre class="language-r">#' @rdname join_keys</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">88</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">132</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    names_diff_inenv &lt;- setdiff(names(x@env), names(y@env))</pre>
+                      <pre class="language-r">#' @order 5</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">89</td>
+                    <td class="num">133</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">90</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">134</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (length(objects_diff)) {</pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">91</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">135</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      error &lt;- c(</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">92</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">136</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        error,</pre>
+                      <pre class="language-r">#' # Setter for join_keys within teal_data ----</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">93</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">137</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        paste0("Object(s) recreated with code that have different structure in ", x_name, ":"),</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">94</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">138</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        paste0("  \u2022 ", names(which(!objects_diff)))</pre>
+                      <pre class="language-r">#' td &lt;- teal_data()</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">95</td>
+                    <td class="num">139</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      )</pre>
+                      <pre class="language-r">#' join_keys(td) &lt;- jk</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">96</td>
+                    <td class="num">140</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">97</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">141</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (length(names_diff_inenv)) {</pre>
+                      <pre class="language-r">#' join_keys(td)["ds1", "ds2"] &lt;- "new_key"</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">98</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">142</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      error &lt;- c(</pre>
+                      <pre class="language-r">#' join_keys(td) &lt;- c(join_keys(td), join_keys(join_key("ds3", "ds2", "key3")))</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">99</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">143</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        error,</pre>
+                      <pre class="language-r">#' join_keys(td)</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">100</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">144</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        paste0("Object(s) not created with code that exist in ", x_name, ":"),</pre>
+                      <pre class="language-r">`join_keys&lt;-.teal_data` &lt;- function(x, value) {</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">101</td>
-                    <td class="coverage">!</td>
+                  <tr class="covered">
+                    <td class="num">145</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        paste0("  \u2022 ", names_diff_inenv)</pre>
+                      <pre class="language-r">  join_keys(x@join_keys) &lt;- value</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">102</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">146</td>
+                    <td class="coverage">2<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      )</pre>
+                      <pre class="language-r">  x</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">103</td>
+                    <td class="num">147</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">104</td>
-                    <td class="coverage">1<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">    if (length(names_diff_other)) {</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">105</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">148</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      error &lt;- c(</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">106</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">149</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        error,</pre>
+                      <pre class="language-r">#' Internal constructor</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">107</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">150</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        paste0("Object(s) created with code that do not exist in ", x_name, ":"),</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">108</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">151</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        paste0("  \u2022 ", names_diff_other)</pre>
+                      <pre class="language-r">#' @return an empty `join_keys` list</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">109</td>
+                    <td class="num">152</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      )</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">110</td>
+                    <td class="num">153</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">111</td>
+                    <td class="num">154</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">new_join_keys &lt;- function() {</pre>
                     </td>
                   </tr>
                   <tr class="covered">
-                    <td class="num">112</td>
-                    <td class="coverage">1<em>x</em></td>
+                    <td class="num">155</td>
+                    <td class="coverage">351<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    stop(paste(error, collapse = "\n"), call. = FALSE)</pre>
+                      <pre class="language-r">  structure(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">113</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">156</td>
+                    <td class="coverage">351<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">    list(),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">114</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">157</td>
+                    <td class="coverage">351<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">})</pre>
+                      <pre class="language-r">    class = c("join_keys", "list"),</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">115</td>
-                    <td class="coverage"></td>
+                  <tr class="covered">
+                    <td class="num">158</td>
+                    <td class="coverage">351<em>x</em></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">setMethod("verify", signature = "qenv.error", definition = function(x) {</pre>
+                      <pre class="language-r">    "parents" = list()</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">116</td>
-                    <td class="coverage">1<em>x</em></td>
+                  <tr class="never">
+                    <td class="num">159</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  stop(conditionMessage(x), call. = FALSE)</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">117</td>
+                    <td class="num">160</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">})</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
                 </tbody>
@@ -16169,35 +16393,35 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">65</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  checkmate::assert_list(data)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">66</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  checkmate::assert_class(join_keys, "join_keys")</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">67</td>
-                    <td class="coverage">42<em>x</em></td>
+                    <td class="coverage">43<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  if (is.null(datanames)) datanames &lt;- character(0) # todo: allow to specify</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">68</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  checkmate::assert_character(datanames)</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">69</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  if (!any(is.language(code), is.character(code))) {</pre>
                     </td>
@@ -16225,7 +16449,7 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">73</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  if (is.language(code)) {</pre>
                     </td>
@@ -16246,7 +16470,7 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">76</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  if (length(code)) {</pre>
                     </td>
@@ -16267,7 +16491,7 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">79</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  verified &lt;- (length(code) == 0L &amp;&amp; length(data) == 0L)</pre>
                     </td>
@@ -16281,7 +16505,7 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">81</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  id &lt;- sample.int(.Machine$integer.max, size = length(code))</pre>
                     </td>
@@ -16295,14 +16519,14 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">83</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  new_env &lt;- rlang::env_clone(list2env(data), parent = parent.env(.GlobalEnv))</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">84</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  lockEnvironment(new_env, bindings = TRUE)</pre>
                     </td>
@@ -16316,70 +16540,70 @@ <h2>teal.data coverage - 78.35%</h2>
                   </tr>
                   <tr class="covered">
                     <td class="num">86</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  methods::new(</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">87</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    "teal_data",</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">88</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    env = new_env,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">89</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    code = code,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">90</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    warnings = rep("", length(code)),</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">91</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    messages = rep("", length(code)),</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">92</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    id = id,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">93</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    join_keys = join_keys,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">94</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    datanames = datanames,</pre>
                     </td>
                   </tr>
                   <tr class="covered">
                     <td class="num">95</td>
-                    <td class="coverage">74<em>x</em></td>
+                    <td class="coverage">75<em>x</em></td>
                     <td class="col-sm-12">
                       <pre class="language-r">    verified = verified</pre>
                     </td>
@@ -16401,153 +16625,160 @@ <h2>teal.data coverage - 78.35%</h2>
                 </tbody>
               </table>
             </div>
-            <div id="R/teal_data-show.R" class="hidden">
+            <div id="R/zzz.R" class="hidden">
               <table class="table-condensed">
                 <tbody>
                   <tr class="never">
                     <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Show `teal_data` object</pre>
+                      <pre class="language-r">.onLoad &lt;- function(libname, pkgname) { # nolint</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">2</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">  # expose default CDISC dataset names</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Prints `teal_data` object</pre>
+                      <pre class="language-r">  # copy from excel file</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">4</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param object (`teal_data`)</pre>
+                      <pre class="language-r">  default_cdisc_keys &lt;- yaml::yaml.load_file(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">5</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @return Input `teal_data` object.</pre>
+                      <pre class="language-r">    system.file("cdisc_datasets/cdisc_datasets.yaml", package = "teal.data")</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @importFrom methods show</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">7</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">  assign("default_cdisc_keys", default_cdisc_keys, envir = parent.env(environment()))</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal_data()</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal_data(x = iris, code = "x = iris")</pre>
+                      <pre class="language-r">  # update default_cdisc_join_keys</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">10</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' verify(teal_data(x = iris, code = "x = iris"))</pre>
+                      <pre class="language-r">  assign(</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">11</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
+                      <pre class="language-r">    "default_cdisc_join_keys",</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">12</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">setMethod("show", signature = "teal_data", function(object) {</pre>
+                      <pre class="language-r">    build_cdisc_join_keys(default_cdisc_keys),</pre>
                     </td>
                   </tr>
                   <tr class="missed">
                     <td class="num">13</td>
                     <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  if (object@verified) {</pre>
+                      <pre class="language-r">    envir = parent.env(environment())</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">14</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    cat("\u2705\ufe0e", "verified teal_data object\n")</pre>
+                      <pre class="language-r">  )</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  } else {</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="missed">
                     <td class="num">16</td>
                     <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    cat("\u2716", "unverified teal_data object\n")</pre>
+                      <pre class="language-r">  invisible()</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">}</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
+                  <tr class="never">
                     <td class="num">18</td>
-                    <td class="coverage">!</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  rlang::env_print(object@env)</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">19</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">})</pre>
+                      <pre class="language-r"># use non-exported function from teal.code</pre>
+                    </td>
+                  </tr>
+                  <tr class="never">
+                    <td class="num">20</td>
+                    <td class="coverage"></td>
+                    <td class="col-sm-12">
+                      <pre class="language-r">lang2calls &lt;- getFromNamespace("lang2calls", "teal.code")</pre>
                     </td>
                   </tr>
                 </tbody>
               </table>
             </div>
-            <div id="R/default_cdisc_join_keys.R" class="hidden">
+            <div id="R/teal_data-show.R" class="hidden">
               <table class="table-condensed">
                 <tbody>
                   <tr class="never">
                     <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' List containing the default `CDISC` join keys</pre>
+                      <pre class="language-r">#' Show `teal_data` object</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -16561,251 +16792,132 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @details</pre>
+                      <pre class="language-r">#' Prints `teal_data` object</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">4</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' This data object is created at loading time from `cdisc_datasets/cdisc_datasets.yaml`.</pre>
+                      <pre class="language-r">#' @param object (`teal_data`)</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @return Input `teal_data` object.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @name default_cdisc_join_keys</pre>
+                      <pre class="language-r">#' @importFrom methods show</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @docType data</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">8</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @export</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">9</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">NULL</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">10</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r"></pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">11</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' Helper method to build `default_cdisc_join_keys`</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">12</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @param default_cdisc_keys (`list`) default definition of primary and foreign</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">13</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' keys for `CDISC` datasets</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">14</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">15</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">16</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">build_cdisc_join_keys &lt;- function(default_cdisc_keys) {</pre>
-                    </td>
-                  </tr>
-                  <tr class="missed">
-                    <td class="num">17</td>
-                    <td class="coverage">!</td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_list(default_cdisc_keys, types = "list")</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">18</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r"></pre>
-                    </td>
-                  </tr>
-                  <tr class="missed">
-                    <td class="num">19</td>
-                    <td class="coverage">!</td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">  jk &lt;- join_keys()</pre>
-                    </td>
-                  </tr>
-                  <tr class="missed">
-                    <td class="num">20</td>
-                    <td class="coverage">!</td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">  for (name in names(default_cdisc_keys)) {</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">21</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">    # Set default primary keys</pre>
-                    </td>
-                  </tr>
-                  <tr class="missed">
-                    <td class="num">22</td>
-                    <td class="coverage">!</td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">    keys_list &lt;- default_cdisc_keys[[name]]</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">23</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @examples</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">24</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">8</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (!is.null(keys_list[["primary"]])) {</pre>
+                      <pre class="language-r">#' teal_data()</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">25</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">9</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      jk[[name]][[name]] &lt;- keys_list[["primary"]]</pre>
+                      <pre class="language-r">#' teal_data(x = iris, code = "x = iris")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">26</td>
+                    <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">#' verify(teal_data(x = iris, code = "x = iris"))</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">27</td>
+                    <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r"></pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
-                  <tr class="missed">
-                    <td class="num">28</td>
-                    <td class="coverage">!</td>
+                  <tr class="never">
+                    <td class="num">12</td>
+                    <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    if (!is.null(keys_list[["parent"]])) {</pre>
+                      <pre class="language-r">setMethod("show", signature = "teal_data", function(object) {</pre>
                     </td>
                   </tr>
                   <tr class="missed">
-                    <td class="num">29</td>
+                    <td class="num">13</td>
                     <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      if (!is.null(keys_list[["foreign"]])) {</pre>
+                      <pre class="language-r">  if (object@verified) {</pre>
                     </td>
                   </tr>
                   <tr class="missed">
-                    <td class="num">30</td>
+                    <td class="num">14</td>
                     <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        jk[[name]][[keys_list[["parent"]]]] &lt;- keys_list[["foreign"]]</pre>
+                      <pre class="language-r">    cat("\u2705\ufe0e", "verified teal_data object\n")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">31</td>
+                    <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      }</pre>
+                      <pre class="language-r">  } else {</pre>
                     </td>
                   </tr>
                   <tr class="missed">
-                    <td class="num">32</td>
+                    <td class="num">16</td>
                     <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      parents(jk)[[name]] &lt;- keys_list[["parent"]]</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">33</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">    }</pre>
+                      <pre class="language-r">    cat("\u2716", "unverified teal_data object\n")</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">34</td>
+                    <td class="num">17</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">  }</pre>
                     </td>
                   </tr>
                   <tr class="missed">
-                    <td class="num">35</td>
+                    <td class="num">18</td>
                     <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  jk</pre>
+                      <pre class="language-r">  rlang::env_print(object@env)</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">36</td>
+                    <td class="num">19</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">}</pre>
+                      <pre class="language-r">})</pre>
                     </td>
                   </tr>
                 </tbody>
               </table>
             </div>
-            <div id="R/utils.R" class="hidden">
+            <div id="R/default_cdisc_join_keys.R" class="hidden">
               <table class="table-condensed">
                 <tbody>
                   <tr class="never">
                     <td class="num">1</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Whether the variable name is good to use within Show R Code</pre>
+                      <pre class="language-r">#' List containing the default `CDISC` join keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
@@ -16819,298 +16931,235 @@ <h2>teal.data coverage - 78.35%</h2>
                     <td class="num">3</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Spaces are problematic because the variables must be escaped</pre>
+                      <pre class="language-r">#' @details</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">4</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' with backticks.</pre>
+                      <pre class="language-r">#' This data object is created at loading time from `cdisc_datasets/cdisc_datasets.yaml`.</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">5</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Also, they should not start with a number as R may silently make</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">6</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' it valid by changing it.</pre>
+                      <pre class="language-r">#' @name default_cdisc_join_keys</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">7</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' Therefore, we only allow alphanumeric characters with underscores.</pre>
+                      <pre class="language-r">#' @docType data</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">8</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' The first character of the `name` must be an alphabetic character</pre>
+                      <pre class="language-r">#' @export</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">9</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' and can be followed by alphanumeric characters.</pre>
+                      <pre class="language-r">NULL</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">10</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">11</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @md</pre>
+                      <pre class="language-r">#' Helper method to build `default_cdisc_join_keys`</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">12</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @param default_cdisc_keys (`list`) default definition of primary and foreign</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">13</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @param name `character, single or vector` name to check</pre>
+                      <pre class="language-r">#' keys for `CDISC` datasets</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">14</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @keywords internal</pre>
+                      <pre class="language-r">#'</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">15</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#'</pre>
+                      <pre class="language-r">#' @keywords internal</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">16</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' @examples</pre>
+                      <pre class="language-r">build_cdisc_join_keys &lt;- function(default_cdisc_keys) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">17</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("aas2df")</pre>
+                      <pre class="language-r">  checkmate::assert_list(default_cdisc_keys, types = "list")</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">18</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL")</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">19</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("ADSLmodified")</pre>
+                      <pre class="language-r">  jk &lt;- join_keys()</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">20</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL_2")</pre>
+                      <pre class="language-r">  for (name in names(default_cdisc_keys)) {</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">21</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("a1")</pre>
+                      <pre class="language-r">    # Set default primary keys</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">22</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' # the following fail</pre>
+                      <pre class="language-r">    keys_list &lt;- default_cdisc_keys[[name]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">23</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' \dontrun{</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">24</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("1a")</pre>
+                      <pre class="language-r">    if (!is.null(keys_list[["primary"]])) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">25</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL.modified")</pre>
+                      <pre class="language-r">      jk[[name]][[name]] &lt;- keys_list[["primary"]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">26</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("ADSL_modified")</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
                     <td class="num">27</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' teal.data:::check_simple_name("a1...")</pre>
+                      <pre class="language-r"></pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">28</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">#' }</pre>
+                      <pre class="language-r">    if (!is.null(keys_list[["parent"]])) {</pre>
                     </td>
                   </tr>
-                  <tr class="never">
+                  <tr class="missed">
                     <td class="num">29</td>
-                    <td class="coverage"></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">check_simple_name &lt;- function(name) {</pre>
+                      <pre class="language-r">      if (!is.null(keys_list[["foreign"]])) {</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
+                  <tr class="missed">
                     <td class="num">30</td>
-                    <td class="coverage">16<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">  checkmate::assert_character(name, min.len = 1, any.missing = FALSE)</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">31</td>
-                    <td class="coverage">16<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">  if (!grepl("^[[:alpha:]][a-zA-Z0-9_]*$", name, perl = TRUE)) {</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">32</td>
-                    <td class="coverage">5<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">    checkmate::makeAssertion(</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">33</td>
-                    <td class="coverage">5<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">      name,</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">34</td>
-                    <td class="coverage">5<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">      paste0(</pre>
-                    </td>
-                  </tr>
-                  <tr class="never">
-                    <td class="num">35</td>
-                    <td class="coverage"></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">        "'",</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">36</td>
-                    <td class="coverage">5<em>x</em></td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        name,</pre>
+                      <pre class="language-r">        jk[[name]][[keys_list[["parent"]]]] &lt;- keys_list[["foreign"]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">37</td>
+                    <td class="num">31</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        "' ",</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">38</td>
-                    <td class="coverage">5<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">        "must only contain alphanumeric characters (with underscores)",</pre>
+                      <pre class="language-r">      }</pre>
                     </td>
                   </tr>
-                  <tr class="covered">
-                    <td class="num">39</td>
-                    <td class="coverage">5<em>x</em></td>
+                  <tr class="missed">
+                    <td class="num">32</td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">        " and the first character must be an alphabetic character"</pre>
+                      <pre class="language-r">      parents(jk)[[name]] &lt;- keys_list[["parent"]]</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">40</td>
+                    <td class="num">33</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">      ),</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">41</td>
-                    <td class="coverage">5<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">      var.name = "name",</pre>
-                    </td>
-                  </tr>
-                  <tr class="covered">
-                    <td class="num">42</td>
-                    <td class="coverage">5<em>x</em></td>
-                    <td class="col-sm-12">
-                      <pre class="language-r">      NULL</pre>
+                      <pre class="language-r">    }</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">43</td>
+                    <td class="num">34</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
-                      <pre class="language-r">    )</pre>
+                      <pre class="language-r">  }</pre>
                     </td>
                   </tr>
-                  <tr class="never">
-                    <td class="num">44</td>
-                    <td class="coverage"></td>
+                  <tr class="missed">
+                    <td class="num">35</td>
+                    <td class="coverage">!</td>
                     <td class="col-sm-12">
-                      <pre class="language-r">  }</pre>
+                      <pre class="language-r">  jk</pre>
                     </td>
                   </tr>
                   <tr class="never">
-                    <td class="num">45</td>
+                    <td class="num">36</td>
                     <td class="coverage"></td>
                     <td class="col-sm-12">
                       <pre class="language-r">}</pre>