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

tests/standalone/io/echo_server_test.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.
 //
 // Echo server test program for testing sockets.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
@@ skipping 82 matching lines @@
 
         handleWrite();
       }
 
       _socket.onData = messageHandler;
       _socket.onError = errorHandler;
       writeMessage();
     }
 
     _socket = new Socket(TestingServer.HOST, _port);
-    if (_socket !== null) {
+    if (_socket != null) {
       _socket.onConnect = connectHandler;
     } else {
       Expect.fail("Socket creation failed");
     }
   }
 
   void initialize() {
     _receivePort.receive((var message, SendPort replyTo) {
       _port = message;
       sendData();
@@ skipping 80 matching lines @@
 
     connection.onData = messageHandler;
     connection.onClosed = closeHandler;
     connection.onError = errorHandler;
   }
 }
 
 main() {
   EchoServerTest.testMain();
 }