Specify the types for Element.classes, Element.elements and Node.nodes

client/html/src/XMLElementWrappingImplementation.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.
 
 class _XMLClassSet extends _CssClassSet {
   _XMLClassSet(element) : super(element);
 
   String _className() {
     final classStr = _element.getAttribute('class');
     return classStr == null ? '' : classStr;
@@ skipping 25 matching lines @@
     return _cssClassSet;
   }
 
   ElementList get elements() {
     if (_elements == null) {
       _elements = new FilteredElementList(this);
     }
     return _elements;
   }
 
-  // TODO: The type of value should be Collection<Element>. See http://b/5392897
-  void set elements(value) {
+  void set elements(Collection<Element> value) {
     final elements = this.elements;
     elements.clear();
     elements.addAll(value);
   }
 
   String get outerHTML() {
     final container = new Element.tag("div");
     // Safari requires that the clone be removed from its owner document before
     // being inserted into the HTML document.
     container.elements.add(this.clone(true).remove());
@@ skipping 125 matching lines @@
 
   void set lang(String value) { attributes['lang'] = value; }
 
   String get dir() => _attr('dir');
 
   void set dir(String value) { attributes['dir'] = value; }
 
   String _attr(String name, [String def = '']) =>
     attributes.containsKey(name) ? attributes[name] : def;
 }