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

samples/swarm/swarm_ui_lib/view/view.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.
 
 library view;
 
 import 'dart:html';
 import 'dart:math' as Math;
 
 import '../base/base.dart';
@@ skipping 38 matching lines @@
     : customStyle = new Map<String, String>();
 
   View.html(String html)
     : customStyle = new Map<String, String>(),
       _node = new Element.html(html);
 
   // TODO(rnystrom): Get rid of this when all views are refactored to not use
   // it.
   Element get node {
     // Lazy render.
-    if (_node === null) {
+    if (_node == null) {
       _render();
     }
 
     return _node;
   }
 
   /**
    * A subclass that contains child views should override this to return those
    * views. View uses this to ensure that child views are properly rendered
    * and initialized when their parent view is without the parent having to
@@ skipping 25 matching lines @@
    * been removed.
    */
   void childViewRemoved(View child) {
     if (isInDocument) {
       child._exitDocument();
     }
   }
 
   /** Gets whether this View has already been rendered or not. */
   bool get isRendered {
-    return _node !== null;
+    return _node != null;
   }
 
   /**
    * Gets whether this View (or one of its parents) has been added to the
    * document or not.
    */
   bool get isInDocument {
-    return _node !== null && node.document.body.contains(node);
+    return _node != null && node.document.body.contains(node);
   }
 
   /**
    * Adds this view to the document as a child of the given node. This should
    * generally only be called once for the top-level view.
    */
   void addToDocument(Element parentNode) {
     assert(!isInDocument);
 
     _render();
@@ skipping 240 matching lines @@
     }
   }
 
   void _applyLayout() {
     if (_layout != null) {
       _layout.applyLayout();
     }
     _applyLayoutToChildren();
   }
 }