void _disposeHold() { _hold = null; }
void _disposeHold() { this._hold = null; }
void _handleDragDown(DragDownDetails details) { D.assert(_drag == null); D.assert(_hold == null); _hold = position.hold(_disposeHold); }
void _handleDragDown(DragDownDetails details) { D.assert(this._drag == null); D.assert(this._hold == null); this._hold = this.position.hold(this._disposeHold); }