anchor.diff:          'item_renderer_containerMouseOut', 
           container.onMouseOut.listen(_mouseOutHandler)
       );
  +    
  +    _streamSubscriptionManager.add(
  +        'item_renderer_containerKey', 
  +        container.onKeyDown.listen(_keyHandler)
  +    );
   
       invokeLaterSingle('invalidateData', invalidateData);
     }
  
positive.code:     notify(
          new FrameworkEvent<MouseEvent>(
              'mouseMove',
              relatedObject: event
          )
      );
  
negative.code:   Stream<FrameworkEvent> get onDataChanged;
    Stream<FrameworkEvent> get onFieldChanged;
    Stream<FrameworkEvent> get onFieldsChanged;
    Stream<FrameworkEvent<MouseEvent>> get onClick;
    Stream<FrameworkEvent<MouseEvent>> get onMouseUp;
    Stream<FrameworkEvent<MouseEvent>> get onMouseDown;
    Stream<FrameworkEvent<MouseEvent>> get onMouseOver;
    Stream<FrameworkEvent<MouseEvent>> get onMouseOut;
    Stream<FrameworkEvent<MouseEvent>> get onMouseMove;
    Stream<FrameworkEvent<KeyboardEvent>> get onKey;
    Stream<FrameworkEvent> get onDataPropertyChanged;
  
    int get index;
  