anchor.diff:    }
   
     void _updateButtonLabel() {
  -    var d = list.selectedData;
  +    var d = selectedData;
       if (d != null) button.text = labelFactory(d); else button.text = defaultLabel;
     }
   }
  
positive.code:     _updateButtonLabel();
    }
  
    void _listItemSelectedHandler(Event event) {
      list.close();
      _updateButtonLabel();
    }
  
    void _pressButtonHandler(Event event) {
  
negative.code: 
  
  class ListPicker extends Component {
  
    EventStream<Event> get onItemSelected => itemSelectedEvent.forTarget(this);
  
    Skin listSkin;
    Skin buttonSkin;
  