Replaced Element.append with Node.appendChild

tests/html/node_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 NodeTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_individual_config.dart';
 import 'dart:html';
 import 'dart:svg' as svg;
 
@@ skipping 21 matching lines @@
       final out = subnode.replaceWith(new Text('Bar'));
       expect(out, equals(subnode), reason: '#replaceWith should be chainable');
       expect(node.nodes.length, 3);
       expect(node.nodes[0], isText);
       expect(node.nodes[0].text, 'Foo');
       expect(node.nodes[1], isText);
       expect(node.nodes[1].text, 'Bar');
       expect(node.nodes[2], isComment);
     });
 
+    test('append', () {
+      var node = makeNode();
+      node.append(new Element.tag('hr'));
+      expect(node.nodes.last, isHRElement);
+    });
+
     test('remove', () {
       final node = makeNodeWithChildren();
       final subnode = node.nodes[1];
       subnode.remove();
       expect(node.nodes.length, 2);
       expect(node.nodes[0], isText);
       expect(node.nodes[1], isComment);
     });
 
     test('contains', () {
@@ skipping 201 matching lines @@
     });
 
     test('getRange', () {
       var range = makeNodeList().getRange(1, 2);
       expect(range, isNodeList);
       expect(range[0], isBRElement);
       expect(range[1], isComment);
     });
   });
 }