anchor.diff:  }
   
   class _DatePickerDialogState extends State<_DatePickerDialog> {
  +  bool _vibrate = false;
  +
     @override
     void initState() {
       super.initState();
  
positive.code:   GlobalKey _pickerKey = new GlobalKey();
  
    void _handleModeChanged(_DatePickerMode mode) {
      HapticFeedback.vibrate();
      setState(() {
        _mode = mode;
      });
    }
  
    void _handleYearChanged(DateTime value) {
      HapticFeedback.vibrate();
      setState(() {
        _mode = _DatePickerMode.day;
        _selectedDate = value;
  
negative.code: 
    @override
    Widget build(BuildContext context) {
      switch (Theme.of(context).platform) {
        case TargetPlatform.android:
        case TargetPlatform.fuchsia:
          _vibrate = true;
          break;
        case TargetPlatform.iOS:
          _vibrate = false;
          break;
      }
      Widget picker = new Flexible(
        child: new SizedBox(
          height: _kMaxDayPickerHeight,
  