anchor.diff:                              defaultPeriod,
                           isDense: true,
                           underline: null,
  -                        items: [20, 30, 45, 60]
  +                        items: _periodValues
                               .map((e) => DropdownMenuItem(
                                     value: e,
                                     child: Text('$e sec'),
  
positive.code:                       value: _digits,
                        isDense: true,
                        underline: null,
                        items: [6, 7, 8]
                            .map((e) => DropdownMenuItem(
                                  value: e,
                                  child: Text('$e digits'),
  
negative.code:   bool _validateSecretLength = false;
    _QrScanState _qrState = _QrScanState.none;
    bool _isObscure = true;
    List<int> _periodValues = [20, 30, 45, 60];
    List<int> _digitsValues = [6, 8];
  
    _scanQrCode(QrScanner qrScanner) async {
      try {
  