anchor.diff:    void _startDragging(BuildContext context, PointerDownEvent event) {
       final SliverReorderableListState? list = SliverReorderableList.maybeOf(context);
       list?.startItemDragReorder(
  -        index: index,
  -        event: event,
  -        recognizer: createRecognizer(),
  +      index: index,
  +      event: event,
  +      recognizer: createRecognizer(),
       );
     }
   }
  
positive.code:     setState(() {
        _overlayEntry?.markNeedsBuild();
        _dragUpdateItems();
        _autoScrollIfNecessary();
      });
    }
  
  
negative.code:   Offset? _finalDropPosition;
    MultiDragGestureRecognizer? _recognizer;
    int? _recognizerPointer;
    // To implement the gap for the dragged item, we replace the dragged item
    // with a zero sized box, and then translate all of the later items down
    // by the size of the dragged item. This allows us to keep the order of the
  