anchor.diff:      properties.add(IterableProperty<String>('listeners', listeners, ifEmpty: '<none>'));
       properties.add(DiagnosticsProperty<MouseCursor>('cursor', cursor, defaultValue: null));
       properties.add(DiagnosticsProperty<bool>('opaque', opaque, defaultValue: true));
  -  }
  -}
  -
  -class _MouseRegionState extends State<MouseRegion> {
  -  void handleExit(PointerExitEvent event) {
  -    if (widget.onExit != null && mounted)
  -      widget.onExit!(event);
  -  }
  -
  -  PointerExitEventListener? getHandleExit() {
  -    return widget.onExit == null ? null : handleExit;
  -  }
  -
  -  @override
  -  Widget build(BuildContext context) {
  -    return _RawMouseRegion(this);
  -  }
  -}
  -
  -class _RawMouseRegion extends SingleChildRenderObjectWidget {
  -  _RawMouseRegion(this.owner) : super(child: owner.widget.child);
  -
  -  final _MouseRegionState owner;
  -
  -  @override
  -  RenderMouseRegion createRenderObject(BuildContext context) {
  -    final MouseRegion widget = owner.widget;
  -    return RenderMouseRegion(
  -      onEnter: widget.onEnter,
  -      onHover: widget.onHover,
  -      onExit: owner.getHandleExit(),
  -      cursor: widget.cursor,
  -      opaque: widget.opaque,
  -    );
  -  }
  -
  -  @override
  -  void updateRenderObject(BuildContext context, RenderMouseRegion renderObject) {
  -    final MouseRegion widget = owner.widget;
  -    renderObject
  -      ..onEnter = widget.onEnter
  -      ..onHover = widget.onHover
  -      ..onExit = owner.getHandleExit()
  -      ..cursor = widget.cursor
  -      ..opaque = widget.opaque;
     }
   }
   
  
positive.code: ///
  ///  * [Listener], a similar widget that tracks pointer events when the pointer
  ///    has buttons pressed.
  class MouseRegion extends StatefulWidget {
    /// Creates a widget that forwards mouse events to callbacks.
    ///
    /// By default, all callbacks are empty, [cursor] is [MouseCursor.defer], and
  
negative.code:     this.onHover,
      this.cursor = MouseCursor.defer,
      this.opaque = true,
      Widget? child,
    }) : assert(cursor != null),
         assert(opaque != null),
         super(key: key, child: child);
  
    /// Triggered when a mouse pointer has entered this widget.
    ///
  