anchor.diff:  
           test('update selection from model', () {
             final template =
  -              dom.document.querySelector('#bindSelectionTemplate') as AutoBindingElement;
  +              dom.document.querySelector('#bindSelectionTemplate')
  +                  as AutoBindingElement;
             final model = template.model = new MyModel();
             final done1 = expectAsync(() {});
   
             return new Future(() {
  -            final list = dom.document.querySelector('#bindSelection') as CoreList;
  +            final list = dom.document.querySelector('#bindSelection')
  +                as CoreList;
   
   // TODO(zoechi) check if this event should be fired when selection was changed
   // probably not because the doc says `Fired when an item element is tapped`
  -// but it is handy during debugging of the test (remove this code when the problem is fixed)
  +// but it is handy during debugging of the test (remove this code when the
  +// problem is fixed)
   //            list.on['core-activate'].first.then((e) {
   //              expect((e.detail as CoreActivateEvent).data, equals(model.data[0]));
   //              done1();
  
positive.code: import 'package:polymer/polymer.dart';
  import 'package:unittest/unittest.dart';
  import 'package:unittest/html_config.dart' show useHtmlConfiguration;
  import 'package:core_elements/core_list_dart.dart' show CoreList, CoreActivateEvent;
  
  class Item {
    String value;
  
negative.code: 
              model.selection = model.data[0];
              return new Future(() {
                final foundSelected =
                    dom.document.querySelector('#bindSelection .selected');
                expect(foundSelected.innerHtml, contains(model.data[0].value));
              });
            });
  