anchor.diff:      sub.cancel();
       invocationCounter = 0;
       element.dispatchEvent(event);
  -    expect(invocationCounter, isZero);
  +    expect(invocationCounter, 0);
   
       provider.forTarget(element).listen(handler);
       invocationCounter = 0;
  
positive.code:     // rely on this. We therefore wrap it into an expectAsync.
      runZoned(expectAsync0(() {
        var zone = Zone.current;
        expect(zone, isNot(equals(Zone.root)));
  
        StreamSubscription<Event> sub;
  
  
negative.code: 
      invocationCounter = 0;
      element.dispatchEvent(event);
      expect(invocationCounter, 0);
  
      var provider = new EventStreamProvider<Event>('test');
  
  