maybeWhen<TResult extends Object?>  method 
- @optionalTypeArgs
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 repo,  String collection,  String rkey,  bool? validate,  Map<String, dynamic> record,  String? swapRecord,  String? swapCommit,  Map<String, dynamic>? $unknown)?  $default,{required TResult orElse(),}) {final _that = this;
switch (_that) {
case _RepoPutRecordInput() when $default != null:
return $default(_that.repo,_that.collection,_that.rkey,_that.validate,_that.record,_that.swapRecord,_that.swapCommit,_that.$unknown);case _:
  return orElse();
}
}