maybeWhen<TResult extends Object?>  method 
    Null safety
- TResult $default( )?,
- {TResult byIndex( )?,
- required TResult orElse(
@optionalTypeArgs, inherited
    Implementation
@optionalTypeArgs
TResult maybeWhen<TResult extends Object?>(
  TResult Function(
          Key? key,
          bool selected,
          Callback? onSelect,
          Callback? onDeselect,
          Callback? onLongPress,
          MaterialStateProperty? color,
          List<DataCell> cells)?
      $default, {
  TResult Function(
          int? index,
          bool selected,
          Callback? onSelect,
          Callback? onDeselect,
          Callback? onLongPress,
          MaterialStateProperty? color,
          List<DataCell> cells)?
      byIndex,
  required TResult orElse(),
}) =>
    throw _privateConstructorUsedError;