anchor.diff:      _gestureMap[pointer]?.reject();
     }
   
  -  void _resolveTap(int pointer, _TapResolution resolution, ui.Point globalPosition) {
  +  void _resolveTap(int pointer, _TapResolution resolution, Point globalPosition) {
       _gestureMap.remove(pointer);
       if (resolution == _TapResolution.tap) {
         if (onTapUp != null)
  
positive.code: import 'pointer_router.dart';
  import 'recognizer.dart';
  
  typedef void GestureTapDownCallback(ui.Point globalPosition);
  typedef void GestureTapUpCallback(ui.Point globalPosition);
  typedef void GestureTapCallback();
  typedef void GestureTapCancelCallback();
  
  
negative.code:   }
  
    bool isWithinTolerance(PointerInputEvent event, double tolerance) {
      Offset offset = event.position - _initialPosition;
      return offset.distance <= tolerance;
    }
  
  