anchor.diff:  
   
   class ListPicker extends Component {
  +
  +  EventStream<Event> get onItemSelected => itemSelectedEvent.forTarget(this);
   
     Skin listSkin;
     Skin buttonSkin;
  
negative.code:     if (buttonSkin == null) buttonSkin = ThemeManager.theme.takeFor(Theme.BUTTON_SKIN);
      if (labelFactory == null) labelFactory = (d) => d.toString();
  
      list
          ..skin = listSkin
          ..data = _data
          ..itemWidth = stage.sourceWidth
          ..onItemSelected.listen(_listItemSelectedHandler);
  
      button
          ..skin = buttonSkin
          ..onPressed.listen(_pressButtonHandler)
          ..text = defaultLabel;
      if (width != 0) button.width = width;
      if (height != 0) button.height = height;
  
      addChild(button);
  
  