maybeWhen<TResult extends Object?>  method 
- @optionalTypeArgs
- TResult postView(- PostView data
 
- required TResult orElse(),
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( PostView data)?  postView,required TResult orElse(),}) {final _that = this;
switch (_that) {
case UModerationSubjectPostPostView() when postView != null:
return postView(_that.data);case _:
  return orElse();
}
}