when<TResult extends Object?>  method 
- @optionalTypeArgs
- TResult $default(- UAdminUpdateSubjectStatusSubject subject,
- StatusAttr? takedown,
- Map<String, dynamic> ? $unknown
 
A switch-like method, using callbacks.
As opposed to map, this offers destructuring.
It is equivalent to doing:
switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}
Implementation
@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function(@UAdminUpdateSubjectStatusSubjectConverter()  UAdminUpdateSubjectStatusSubject subject, @StatusAttrConverter()  StatusAttr? takedown,  Map<String, dynamic>? $unknown)  $default,) {final _that = this;
switch (_that) {
case _AdminUpdateSubjectStatusOutput():
return $default(_that.subject,_that.takedown,_that.$unknown);case _:
  throw StateError('Unexpected subclass');
}
}