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

tests/standalone/io/socket_stream_close_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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 //
 // Test socket close events.
@@ skipping 124 matching lines @@
           _socket.outputStream.onNoPendingWrites = () {
             _socket.outputStream.close();
           };
           break;
         default:
           Expect.fail("Unknown test mode");
       }
     }
 
     _socket = new Socket(SocketCloseServer.HOST, _port);
-    Expect.equals(true, _socket !== null);
+    Expect.equals(true, _socket != null);
     _socket.onConnect = connectHandler;
   }
 
   void initialize() {
     _receivePort.receive((var message, SendPort replyTo) {
       _port = message;
       proceed();
     });
     _sendPort.send(_mode, _receivePort.toSendPort());
   }
@@ skipping 206 matching lines @@
   void dispatch(message, replyTo) {
     _donePort = replyTo;
     if (message != SERVERSHUTDOWN) {
       _readBytes = 0;
       _errorEvents = 0;
       _dataEvents = 0;
       _closeEvents = 0;
       _iterations = 0;
       _mode = message;
       _server = new ServerSocket(HOST, 0, 10);
-      Expect.equals(true, _server !== null);
+      Expect.equals(true, _server != null);
       _server.onConnection = (connection) {
         var data = new ConnectionData(connection);
         connectionHandler(data);
       };
       _server.onError = errorHandlerServer;
       replyTo.send(_server.port, null);
     } else {
       new Timer(0, waitForResult);
     }
   }
@@ skipping 25 matching lines @@
   var tests = 9;
   var port = new ReceivePort();
   var completed = 0;
   port.receive((message, ignore) {
     if (++completed == tests) port.close();
   });
   for (var i = 0; i < tests; i++) {
     new SocketClose.start(i, port.toSendPort());
   }
 }