maybeWhen<TResult extends Object?>  method 
      
  
TResult
maybeWhen<TResult extends Object?>(})
      
      
    
A variant of when that fallback to an orElse callback.
It is equivalent to doing:
switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return orElse();
}
Implementation
@optionalTypeArgs
TResult maybeWhen<TResult extends Object?>(
  TResult Function(String placeholder, String title, String okBtnText,
          String cancelBtnText)?
      $default, {
  required TResult orElse(),
}) {
  final _that = this;
  switch (_that) {
    case _AskStringDialogParams() when $default != null:
      return $default(_that.placeholder, _that.title, _that.okBtnText,
          _that.cancelBtnText);
    case _:
      return orElse();
  }
}