anchor.diff:  
           // The grabing area
           Positioned(
  -          left: 0,
  -          right: 0,
  -          height: widget.grabbingHeight,
  -          bottom: _currentDragAmount,
  -          child: _wrapDraggable(false, widget.grabbing, SnappingSheetListenerType.draggable)
  -        ),
  +            left: 0,
  +            right: 0,
  +            height: widget.grabbingHeight,
  +            bottom: _currentDragAmount,
  +            child: _wrapDraggable(
  +                false, widget.grabbing, SnappingSheetListenerType.draggable)),
   
           // The sheet below
           widget.sheetAbove != null
  
positive.code:     }
    }
  
    Widget _wrapDraggable(bool ignoreGestureDetection, Widget child, SnappingSheetListenerType listenerType)  {
  
      if (ignoreGestureDetection) {
        return child;
      }
  
negative.code:   _SnappingSheetState createState() => _SnappingSheetState();
  }
  
  enum SnappingSheetListenerType { draggable, sheetAbove, sheetBelow }
  
  class _SnappingSheetState extends State<SnappingSheet>
      with SingleTickerProviderStateMixin {
    /// How heigh up the sheet is dragged in pixels
    double _currentDragAmount;
  
  