anchor.diff:    }
   
     // TODO(ussuri): Redo once the TODO before #aceContainer in *.html is done.
  -  void onOutlineSizeUpdate(CustomEvent e) {
  +  void _onOutlineSizeUpdate(CustomEvent e) {
       syncPrefs.setValue('outlineSize', e.detail['targetSize'].toString());
       // The top-level [spark-split-view] in [_ui] also listens to the same event.
       e.stopImmediatePropagation();
  
positive.code:     syncPrefs.getValue('splitViewPosition', '300').then((String position) {
        int value = int.parse(position, onError: (_) => null);
        if (value != null) {
          _ui..splitViewPosition = value..deliverChanges();
        }
      });
    }
  
negative.code:     syncPrefs.getValue('outlineSize', '200').then((String position) {
        int value = int.parse(position, onError: (_) => null);
        if (value != null) {
          outlineResizer
              ..targetSize = value
              ..deliverChanges();
        }
      });
      outlineResizer.on['update'].listen(_onOutlineSizeUpdate);
    }
  
    @override
  