anchor.diff:        expect(element.myInts, [1, 4, 3]);
         expect(element.jsElement['myInts'], [1, 4, 3]);
       });
  +
  +    test('List.index', () {
  +      element.add('myThings', new Thing("A"));
  +      element.add('myThings', new Thing("B"));
  +      element.add('myThings', new Thing("C"));
  +      element.set("myThings.1.field","D");
  +      element.removeAt('myThings',0);
  +      element.set('myThings.1.field',"E");
  +
  +      expect(element.myThings.map((Thing t )=> t.field).toList(),["D","E"]);
  +    },skip:"Until https://github.com/Polymer/polymer/issues/2490 is fixed");
  +
  +    test('List.replace', () {
  +      element.add('myThings', new Thing("A"));
  +      element.add('myThings', new Thing("B"));
  +      element.add('myThings', new Thing("C"));
  +      element.set("myThings.1",new Thing("D"));
  +      element.removeAt('myThings',0);
  +      element.set('myThings.1',new Thing("E"));
  +
  +      expect(element.myThings.map((Thing t )=> t.field).toList(),["D","E"]);
  +    },skip:"Until https://github.com/Polymer/polymer/issues/2490 is fixed");
   
       test('JsProxy', () {
         var newModel = new Model('world');
  
positive.code:   });
  }
  
  @PolymerRegister('test-element')
  class TestElement extends HtmlElement with PolymerMixin, PolymerBase, JsProxy {
    @property
  
negative.code:       expect(element.jsElement['myMap']['hello'], 'world');
      });
  
      test('List',  () {
        element.set('myInts', [1, 2, 3]);
        expect(element.myInts, [1, 2, 3]);
        expect(element.jsElement['myInts'], [1, 2, 3]);
  