anchor.diff:          testDiv.append(template.createInstance(model,
               new PolymerExpressions()));
   
  -        return new Future(() {});
  +        return _nextMicrotask(null);
         }, onError: (e) {
           expect('$e', startsWith("Error evaluating expression 'foo':"));
           completer.complete(true);
  
positive.code:         subscription.cancel();
        });
      });
    });
  });
  
  @reflectable
  class NotifyModel extends ChangeNotifier {
  
negative.code:           '<template><span>{{x}}</span></template>'));
        testDiv.append(template.createInstance(model, new PolymerExpressions()));
  
        var el;
        return new Future(() {
          el = testDiv.query("span");
          expect(el.text, 'abcde');
          expect(model.x, 'abcde');
          model.x = '___';
        }).then(_nextMicrotask).then((_) {
          expect(model.x, '___');
          expect(el.text, '___');
        });
      });
  
  