use .append instead of .nodes.add

tests/html/event_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 EventTest;
 import "package:expect/expect.dart";
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:html';
 
@@ skipping 126 matching lines @@
     expect(ev.relatedNode.tagName, 'DIV');
     expect.equals(ev.prevValue, 'red');
     expect.equals(ev.newValue, 'blue');
     expect.equals(ev.attrName, 'color');
     expect.equals(ev.attrChange, equals(MutationEvent.MODIFICATION));
   });
 
   test('DOMMutationEvent', () {
     var div = new DivElement();
     div.on['DOMSubtreeModified'].add(expectAsync1((DOMMutationEvent e) {}));
-    div.nodes.add(new SpanElement());
+    div.append(new SpanElement());
   });
 
   // Issue 1005.
   // eventTest('OverflowEvent',
   //     () => new OverflowEvent(OverflowEvent.BOTH, true, true),
   //     (ev) {
   //   expect(ev.orient, OverflowEvent.BOTH);
   //   expect(ev.horizontalOverflow, isTrue);
   //   expect(ev.verticalOverflow, isTrue);
   // }, type: 'overflowchanged');
@@ skipping 65 matching lines @@
     expect(ev.metaKey, isTrue);
   }, type: 'mousewheel');
 
   // HttpRequestProgressEvent has no properties to itself, so just test that
   // it doesn't error out on creation and can be dispatched.
   // Issue 1005.
   // eventTest('HttpRequestProgressEvent',
   //     () => new HttpRequestProgressEvent('foo', 5),
   //     (ev) {});
 }