Added methods to get keep_on_death

pom.xml

@@ -8,7 +8,7 @@
 
     <groupId>dev.lone</groupId>
     <artifactId>api-itemsadder</artifactId>
-    <version>3.6.2-beta-r3</version>
+    <version>3.6.2-beta-r3-b</version>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

src/main/java/dev/lone/itemsadder/api/ItemsAdder.java

@@ -357,6 +357,26 @@ public static String getLiquidName(Location location)
         throw new NotActuallyItemsAdderException();
     }
 
+    /**
+     * Check if a custom item has keep_on_death behaviour enabled.
+     * @param itemStack the custom item
+     * @return true if it has 'keep_on_death: true', false if not or if it's not a custom item
+     */
+    public static boolean hasKeepOnDeath(ItemStack itemStack)
+    {
+        throw new NotActuallyItemsAdderException();
+    }
+
+    /**
+     * Check if a custom item has keep_on_death behaviour enabled.
+     * @param namespacedId Namespace and ID in the format {@code namespace:id} of the custom item
+     * @return true if it has 'keep_on_death: true', false if not or if it's not a custom item
+     */
+    public static boolean hasKeepOnDeath(String namespacedId)
+    {
+        throw new NotActuallyItemsAdderException();
+    }
+
     /**
      * Applies the Resource pack set for ItemsAdder to the provided player.
      *