diff --git a/CHANGELOG.md b/CHANGELOG.md
index 704b77b..63980e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,25 @@
+## 1.0.0-dev.3
+- **BREAKING**: Renamed extensions from `<Class>Extension` to `<Class>InstanceMembers`.
+- `AbortSignal`
+  - Added `timeout` constructor-like method.
+  - Added `abort` constructor-like method.
+  - Added `aborted` property.
+  - Added `reason` property.
+  - Added `throwIfAborted` method.
+- `AbortController`
+  - Added docs.
+- `fetch()` added docs.
+- `Response`
+  - Fixed internal definition for `_formData` method.
+  - Added docs.
+- `Headers`
+  - Added docs.
+  - Add methods `headersFromMap` and `headersFromArray` to support Dart 2.19.
+- `Iterator` and `IteratorResult`
+  - Added docs.
+- `ReadableStreamDefaultReader` and `ReadableStreamDefaultReaderChunk`
+  - Added docs.
+
 ## 1.0.0-dev.2
 
 - Downgraded `js` dependency to `^0.6.5`.
diff --git a/README.md b/README.md
index 30318db..d463a12 100644
--- a/README.md
+++ b/README.md
@@ -1,15 +1,17 @@
 # Fetch API.
 
+> ⚠️ Requires Dart 2.19 or higher.
+
 This package provides JavaScript bindings to [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API).
 
 ## Features
 
 * Full request parameters coverage
-* Abort requests
+* Support canceling requests
 * Read response
   * As text
-  * As Blob
-  * As Stream of Uint8List
+  * As `Blob`
+  * As `Stream` of `Uint8List`
 * Support streaming of data
 * Get access to redirect status
-* Support non-200 responses
+* Support non-`200` responses
diff --git a/lib/src/abort_controller.dart b/lib/src/abort_controller.dart
index a2e195c..b639fc0 100644
--- a/lib/src/abort_controller.dart
+++ b/lib/src/abort_controller.dart
@@ -2,6 +2,12 @@ import '_js.dart';
 import 'abort_signal.dart';
 
 
+/// The [AbortController] interface represents a controller object that allows
+/// you to abort one or more Web requests as and when desired.
+/// 
+/// You can create a new [AbortController] object using the `AbortController()`
+/// constructor. Communicating with a DOM request is done using an [AbortSignal]
+/// object.
 @JS()
 @staticInterop
 class AbortController {
@@ -9,8 +15,8 @@ class AbortController {
   external factory AbortController();
 }
 
-extension AbortControllerExtension on AbortController {
-  /// Returns an `AbortSignal` object instance, which can be used to
+extension AbortControllerInstanceMembers on AbortController {
+  /// Returns an [AbortSignal] object instance, which can be used to
   /// communicate with, or to abort, a DOM request.
   external final AbortSignal signal;
 
diff --git a/lib/src/abort_signal.dart b/lib/src/abort_signal.dart
index 603ee0d..d726f7c 100644
--- a/lib/src/abort_signal.dart
+++ b/lib/src/abort_signal.dart
@@ -1,8 +1,37 @@
 import '_js.dart';
+import 'abort_controller.dart';
 
 
+/// The [AbortSignal] interface represents a signal object that allows you
+/// to communicate with a DOM request (such as a fetch request) and abort it
+/// if required via an [AbortController] object.
 @JS()
 @staticInterop
 class AbortSignal {
-  external factory AbortSignal();
+  /// Returns an [AbortSignal] instance that will automatically abort
+  /// after a specified [time].
+  factory AbortSignal.timeout(Duration time)
+    => AbortSignal._timeout(time.inMilliseconds);
+
+  /// Returns an [AbortSignal] instance that is already set as aborted.
+  external static AbortSignal abort([dynamic reason]);
+
+  /// Returns an [AbortSignal] instance that will automatically abort
+  /// after a specified [time] in milliseconds.
+  @JS('timeout')
+  external static AbortSignal _timeout(int time);
+}
+
+
+extension AbortSignalInstanceMembers on AbortSignal {
+  /// A [bool] that indicates whether the request(s) the signal is
+  /// communicating with is/are aborted (`true`) or not (`false`).
+  external final bool aborted;
+
+  /// A JavaScript value providing the abort reason, once the signal has aborted.
+  external final dynamic reason;
+
+  /// Throws the signal's abort [reason] if the signal has been aborted;
+  /// otherwise it does nothing.
+  external void throwIfAborted();
 }
diff --git a/lib/src/fetch.dart b/lib/src/fetch.dart
index d5f2bad..1dbf2d8 100644
--- a/lib/src/fetch.dart
+++ b/lib/src/fetch.dart
@@ -6,5 +6,25 @@ import 'response.dart';
 @JS('fetch')
 external Promise<Response> _fetch(dynamic resource, RequestInit? options);
 
+/// The global `fetch()` method starts the process of fetching a resource
+/// from the network, returning a promise which is fulfilled once the response
+/// is available.
+/// 
+/// The promise resolves to the [Response] object representing the response
+/// to your request.
+/// 
+/// A `fetch()` promise only rejects when a network error is encountered
+/// (which is usually when there's a permissions issue or similar).
+/// A `fetch()` promise does not reject on HTTP errors (`404`, etc.).
+/// Instead, a then() handler must check the [ResponseInstanceMembers.ok] and/or
+/// [ResponseInstanceMembers.status] properties.
+/// 
+/// `WindowOrWorkerGlobalScope` is implemented by both `Window` and
+/// `WorkerGlobalScope`, which means that the `fetch()` method is available
+/// in pretty much any context in which you might want to fetch resources.
+/// 
+/// The `fetch()` method is controlled by the `connect-src` directive of
+/// Content Security Policy rather than the directive of the resources
+/// it's retrieving.
 Future<Response> fetch(dynamic resource, [RequestInit? options]) =>
   promiseToFuture(_fetch(resource, options));
diff --git a/lib/src/headers.dart b/lib/src/headers.dart
index 63412b3..d8a076e 100644
--- a/lib/src/headers.dart
+++ b/lib/src/headers.dart
@@ -1,40 +1,54 @@
 import '_js.dart';
 import 'iterator.dart' as js;
 import 'iterator_wrapper.dart';
-
-
+import 'response.dart';
+
+
+/// The [Headers] interface of the Fetch API allows you to perform various
+/// actions on HTTP request and response headers. These actions include
+/// retrieving, setting, adding to, and removing headers from the list of
+/// the request's headers.
+/// 
+/// A [Headers] object has an associated header list, which is initially empty
+/// and consists of zero or more name and value pairs. You can add to this using
+/// methods like `append()`. In all methods of this interface, header names are
+/// matched by case-insensitive byte sequence.
+/// 
+/// For security reasons, some headers can only be controlled by the user agent.
+/// These headers include the forbidden header names and forbidden response
+/// header names.
+/// 
+/// A [Headers] object also has an associated guard, which takes
+/// a value of `immutable`, `request`, `request-no-cors`, `response`, or `none`.
+/// This affects whether the `set()`, `delete()`, and `append()` methods will
+/// mutate the header.
+/// 
+/// You can retrieve a [Headers] object via the `Request.headers` and
+/// [ResponseInstanceMembers.headers] properties, and create
+/// a new [Headers] object using the `Headers()` constructor.
 @JS()
 @staticInterop
 class Headers {
-  /// Creates empty [Headers].
-  factory Headers() => Headers._();
-
-  /// Creates [Headers] from [Map].
-  factory Headers.fromMap(Map<String, String> init) =>
-    Headers._init(init.toJsObject());
-
-  /// Creates [Headers] from array of 2 items arrays. 
-  factory Headers.fromArray(List<List<String>> init) {
-    final _init = JsArray<JsArray<dynamic>>();
-    for (final header in init) {
-      if (header.length != 2)
-        throw Exception('Bad argument');
-
-      _init.add(header.toJsArray());
-    }
-    return Headers._init(_init);
-  }
-
   /// Creates a new [Headers] object.
   @JS('Headers')
-  external factory Headers._();
+  external factory Headers();
 
   /// Creates a new [Headers] object.
   @JS('Headers')
   external factory Headers._init(dynamic init);
+
+  /// Warning: available only with Dart 3.0 or higher.
+  /// Creates [Headers] from [Map].
+  factory Headers.fromMap(Map<String, String> init) =>
+    headersFromMap(init);
+
+  /// Warning: available only with Dart 3.0 or higher.
+  /// Creates [Headers] from array of 2 items arrays. 
+  factory Headers.fromArray(List<List<String>> init) =>
+    headersFromArray(init);
 }
 
-extension HeadersExtension on Headers {
+extension HeadersInstanceMembers on Headers {
   /// Appends a new value onto an existing header inside a [Headers] object,
   /// or adds the header if it does not already exist.
   external void append(String name, String value);
@@ -42,8 +56,8 @@ extension HeadersExtension on Headers {
   /// Deletes a header from a [Headers] object.
   external void delete(String name);
 
-  /// Returns an `iterator` allowing to go through all key/value pairs contained
-  /// in this object.
+  /// Returns an [js.Iterator] allowing to go through all key/value pairs
+  /// contained in this object.
   @JS('entries')
   external js.Iterator<List<String>> _entries();
 
@@ -57,8 +71,8 @@ extension HeadersExtension on Headers {
   /// a certain header.
   external bool has(String name);
 
-  /// Returns an `iterator` allowing you to go through all keys of the key/value
-  /// pairs contained in this object.
+  /// Returns an [js.Iterator] allowing you to go through all keys of
+  /// the key/value pairs contained in this object.
   @JS('keys')
   external js.Iterator<String> _keys();
 
@@ -66,7 +80,7 @@ extension HeadersExtension on Headers {
   /// or adds the header if it does not already exist.
   external void set(String name, String value);
 
-  /// Returns an `iterator` allowing you to go through all values of
+  /// Returns an [js.Iterator] allowing you to go through all values of
   /// the key/value pairs contained in this object.
   @JS('values')
   external js.Iterator<String> _values();
@@ -83,3 +97,19 @@ extension HeadersExtension on Headers {
   /// the key/value pairs contained in this object.
   IteratorWrapper<String> values() => IteratorWrapper(_values());
 }
+
+/// Creates [Headers] from [Map].
+Headers headersFromMap(Map<String, String> init) =>
+  Headers._init(init.toJsObject());
+
+/// Creates [Headers] from array of 2 items arrays. 
+Headers headersFromArray(List<List<String>> init) {
+  final _init = JsArray<JsArray<dynamic>>();
+  for (final header in init) {
+    if (header.length != 2)
+      throw Exception('Bad argument');
+
+    _init.add(header.toJsArray());
+  }
+  return Headers._init(_init);
+}
diff --git a/lib/src/iterator.dart b/lib/src/iterator.dart
index efa3e73..591ec54 100644
--- a/lib/src/iterator.dart
+++ b/lib/src/iterator.dart
@@ -2,14 +2,21 @@ import '_js.dart';
 import 'iterator_result.dart';
 
 
+/// The iterator protocol defines a standard way to produce a sequence of values
+/// (either finite or infinite), and potentially a return value when all values
+/// have been generated.
+/// 
+/// All iterator protocol methods (`next()`, `return()`, and `throw()`) are
+/// expected to return an object implementing the [IteratorResult] interface.
 @JS()
 @anonymous
 class Iterator<T> {
   /// A function that accepts zero or one argument and returns an object
   /// conforming to the [IteratorResult] interface.
   /// 
-  /// If a non-object value gets returned (such as false or undefined)
-  /// when a built-in language feature (such as for...of) is using the iterator,
-  /// a TypeError ("iterator.next() returned a non-object value") will be thrown.
+  /// If a non-object value gets returned (such as `false` or `undefined`)
+  /// when a built-in language feature (such as `for...of`) is using
+  /// the iterator, a `TypeError` (`"iterator.next() returned a non-object
+  /// value"`) will be thrown.
   external IteratorResult<T> next();
 }
diff --git a/lib/src/iterator_result.dart b/lib/src/iterator_result.dart
index fa83cc9..4360018 100644
--- a/lib/src/iterator_result.dart
+++ b/lib/src/iterator_result.dart
@@ -1,6 +1,13 @@
 import '_js.dart';
 
 
+/// In practice, neither property is strictly required; if an object without
+/// either property is returned, it's effectively equivalent to
+/// `{ done: false, value: undefined }`.
+/// 
+/// If an iterator returns a result with `done: true`, any subsequent calls
+/// to `next()` are expected to return `done: true` as well, although
+/// this is not enforced on the language level.
 @JS()
 @anonymous
 class IteratorResult<T> {
diff --git a/lib/src/iterator_wrapper.dart b/lib/src/iterator_wrapper.dart
index f5afd97..c4ce249 100644
--- a/lib/src/iterator_wrapper.dart
+++ b/lib/src/iterator_wrapper.dart
@@ -4,7 +4,7 @@ import 'dart:core' as core;
 import 'iterator.dart' as js;
 
 
-/// Wrapper on top of JS iterator, providing [Iterable] and [Iterator] APIs.
+/// Wrapper on top of [js.Iterator], implementing [Iterable] and [Iterator] APIs.
 class IteratorWrapper<T> extends IterableBase<T> implements core.Iterator<T> {
   IteratorWrapper(this._iterator);
 
diff --git a/lib/src/readable_stream.dart b/lib/src/readable_stream.dart
index 039d53f..a6e218b 100644
--- a/lib/src/readable_stream.dart
+++ b/lib/src/readable_stream.dart
@@ -1,7 +1,11 @@
 import '_js.dart';
 import 'readable_stream_default_reader.dart';
+import 'response.dart';
 
 
+/// The [ReadableStream] interface of the Streams API represents a readable
+/// stream of byte data. The Fetch API offers a concrete instance of
+/// a [ReadableStream] through the body property of a [Response] object.
 @JS()
 @staticInterop
 class ReadableStream {
@@ -12,7 +16,7 @@ class ReadableStream {
   ]);
 }
 
-extension ReadableStreamExtension on ReadableStream {
+extension ReadableStreamInstanceMembers on ReadableStream {
   /// Returns a [bool] indicating whether or not the readable stream
   /// is locked to a reader.
   external final bool locked;
diff --git a/lib/src/readable_stream_default_reader.dart b/lib/src/readable_stream_default_reader.dart
index 190267e..5b6ab3f 100644
--- a/lib/src/readable_stream_default_reader.dart
+++ b/lib/src/readable_stream_default_reader.dart
@@ -5,6 +5,12 @@ import 'readable_stream.dart';
 import 'readable_stream_default_reader_chunk.dart';
 
 
+/// The [ReadableStreamDefaultReader] interface of the Streams API represents
+/// a default reader that can be used to read stream data supplied from
+/// a network (such as a fetch request).
+/// 
+/// A [ReadableStreamDefaultReader] can be used to read from a [ReadableStream]
+/// that has an underlying source of any type.
 @JS()
 @staticInterop
 class ReadableStreamDefaultReader {
@@ -12,7 +18,7 @@ class ReadableStreamDefaultReader {
   external factory ReadableStreamDefaultReader(ReadableStream stream);
 }
 
-extension ReadableStreamDefaultReaderExtension on ReadableStreamDefaultReader {
+extension ReadableStreamDefaultReaderInstanceMembers on ReadableStreamDefaultReader {
   /// Returns a `Promise` that fulfills when the stream closes,
   /// or rejects if the stream throws an error or the reader's lock is released.
   /// This property enables you to write code that responds to an end to
diff --git a/lib/src/readable_stream_default_reader_chunk.dart b/lib/src/readable_stream_default_reader_chunk.dart
index 71fe44f..046a0ba 100644
--- a/lib/src/readable_stream_default_reader_chunk.dart
+++ b/lib/src/readable_stream_default_reader_chunk.dart
@@ -1,7 +1,15 @@
 import 'dart:typed_data';
 import '_js.dart';
+import 'readable_stream_default_reader.dart';
 
 
+/// Describes chunk from [ReadableStreamDefaultReaderInstanceMembers.read].
+/// 
+/// If a chunk is available, then object will be of the form 
+/// `{ value: theChunk, done: false }`.
+/// 
+/// If the stream becomes closed, the object will be of the form
+/// `{ value: undefined, done: true }`.
 @JS()
 @anonymous
 class ReadableStreamDefaultReaderChunk {
diff --git a/lib/src/request_init/request_init.dart b/lib/src/request_init/request_init.dart
index e46ffea..466447e 100644
--- a/lib/src/request_init/request_init.dart
+++ b/lib/src/request_init/request_init.dart
@@ -113,7 +113,7 @@ class RequestInit {
   external AbortSignal? signal;
 }
 
-extension RequestInitExtension on RequestInit {
+extension RequestInitInstanceMembers on RequestInit {
   /// The mode you want to use for the request
   RequestMode get requestMode => RequestMode.from(mode);
   set requestMode(RequestMode requestMode) =>
diff --git a/lib/src/response/response.dart b/lib/src/response/response.dart
index cb273fa..de92672 100644
--- a/lib/src/response/response.dart
+++ b/lib/src/response/response.dart
@@ -8,15 +8,27 @@ import 'response_options.dart';
 import 'response_type.dart';
 
 
+/// The [Response] interface of the Fetch API represents the response
+/// to a request.
+/// 
+/// You can create a new [Response] object using the `Response()` constructor,
+/// but you are more likely to encounter a [Response] object being returned
+/// as the result of another API operation —for example, a service worker
+/// `FetchEvent.respondWith`, or a simple `fetch()`.
 @JS()
 @staticInterop
 class Response {
+  /// Creates a new [Response] object.
   external factory Response([dynamic body, ResponseOptions? options]);
+
+  /// Returns a new [Response] object associated with a network error.
   external static Response error();
+
+  /// Creates a new response with a different URL.
   external static Response redirect(String url, [int status = 302]);
 }
 
-extension ResponseExtension on Response {
+extension ResponseInstanceMembers on Response {
   /// A [ReadableStream] of the body contents.
   external final ReadableStream? body;
 
@@ -67,7 +79,7 @@ extension ResponseExtension on Response {
   /// Returns a promise that resolves with a [FormData] representation of
   /// the response body.
   @JS('formData')
-  external Promise<Blob> _formData();
+  external Promise<FormData> _formData();
 
   /// Returns a promise that resolves with the result of parsing the response
   /// body text as JSON.
diff --git a/pubspec.yaml b/pubspec.yaml
index 15dbd5e..473329e 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: fetch_api
 description: JavaScript bindings for Fetch API, allowing a flexible HTTP requests.
-version: 1.0.0-dev.2
+version: 1.0.0-dev.3
 homepage: https://github.com/Zekfad/fetch_api
 repository: https://github.com/Zekfad/fetch_api
 issue_tracker: https://github.com/Zekfad/fetch_api/issues
@@ -10,7 +10,7 @@ platforms:
   web:
 
 environment:
-  sdk: '>=2.18.0 <4.0.0'
+  sdk: '>=2.19.0-0 <4.0.0'
 
 dependencies:
   js: ^0.6.5