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

tests/corelib/queue_test.dart

 // Copyright (c) 2011, 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.
 
 #library("QueueTest.dart");
 #import("dart:coreimpl");
 
 class QueueTest {
 
   static testMain() {
@@ skipping 156 matching lines @@
 
   static testQueueElements() {
     DoubleLinkedQueue<int> queue1 = new DoubleLinkedQueue<int>.from([1, 2, 4]);
     DoubleLinkedQueue<int> queue2 = new DoubleLinkedQueue<int>();
     queue2.addAll(queue1);
 
     Expect.equals(queue1.length, queue2.length);
     DoubleLinkedQueueEntry<int> entry1 = queue1.firstEntry();
     DoubleLinkedQueueEntry<int> entry2 = queue2.firstEntry();
     while (entry1 != null) {
-      Expect.equals(true, entry1 !== entry2);
+      Expect.equals(true, !identical(entry1, entry2));
       entry1 = entry1.nextEntry();
       entry2 = entry2.nextEntry();
     }
     Expect.equals(null, entry2);
   }
 }
 
 main() {
   QueueTest.testMain();
 }