a === b -> identical(a, b)

sdk/lib/io/chunked_stream.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class _ChunkedInputStream implements ChunkedInputStream {
   _ChunkedInputStream(InputStream this._input, int this._chunkSize)
       : _bufferList = new _BufferList() {
     _input.onClosed = _onClosed;
   }
 
@@ skipping 33 matching lines @@
   void set onClosed(void callback()) {
     _clientCloseHandler = callback;
   }
 
   void set onError(void callback(e)) {
     _input.onError = callback;
   }
 
   void _onData() {
     _readData();
-    if (_bufferList.length >= _chunkSize && _clientDataHandler !== null) {
+    if (_bufferList.length >= _chunkSize && _clientDataHandler != null) {
       _clientDataHandler();
     }
     _checkScheduleCallback();
     _checkInstallDataHandler();
   }
 
   void _readData() {
     List<int> data = _input.read();
-    if (data !== null) {
+    if (data != null) {
       _bufferList.add(data);
     }
   }
 
   void _onClosed() {
     _inputClosed = true;
-    if (_bufferList.length == 0 && _clientCloseHandler !== null) {
+    if (_bufferList.length == 0 && _clientCloseHandler != null) {
       _clientCloseHandler();
       _closed = true;
     } else {
       _checkScheduleCallback();
     }
   }
 
   void _checkInstallDataHandler() {
-    if (_clientDataHandler === null) {
+    if (_clientDataHandler == null) {
       _input.onData = null;
     } else {
       if (_bufferList.length < _chunkSize && !_inputClosed) {
         _input.onData = _onData;
       } else {
         _input.onData = null;
       }
     }
   }
 
   void _checkScheduleCallback() {
     // TODO(sgjesse): Find a better way of scheduling callbacks from
     // the event loop.
     void issueDataCallback(Timer timer) {
       _scheduledDataCallback = null;
-      if (_clientDataHandler !== null) {
+      if (_clientDataHandler != null) {
         _clientDataHandler();
         _checkScheduleCallback();
       }
     }
 
     void issueCloseCallback(Timer timer) {
       _scheduledCloseCallback = null;
       if (!_closed) {
-        if (_clientCloseHandler !== null) _clientCloseHandler();
+        if (_clientCloseHandler != null) _clientCloseHandler();
         _closed = true;
       }
     }
 
     // Schedule data callback if enough data in buffer.
     if ((_bufferList.length >= _chunkSize ||
          (_bufferList.length > 0 && _inputClosed)) &&
-        _clientDataHandler !== null &&
+        _clientDataHandler != null &&
         _scheduledDataCallback == null) {
       _scheduledDataCallback = new Timer(0, issueDataCallback);
     }
 
     // Schedule close callback if no more data and input is closed.
     if (_bufferList.length == 0 &&
         _inputClosed &&
         !_closed &&
         _scheduledCloseCallback == null) {
       if (_scheduledDataCallback != null) {
         _scheduledDataCallback.cancel();
       }
       _scheduledCloseCallback = new Timer(0, issueCloseCallback);
     }
   }
 
   InputStream _input;
   _BufferList _bufferList;
   int _chunkSize;
   bool _inputClosed = false;  // Is the underlying input stream closed?
   bool _closed = false;  // Has the close handler been called?.
   Timer _scheduledDataCallback;
   Timer _scheduledCloseCallback;
   Function _clientDataHandler;
   Function _clientCloseHandler;
 }