whenOrNull<TResult extends Object?> method

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? $default(@JsonKey.new(name: 'data') List<UpdatedBook> updates, int? total, int page, @JsonKey.new(name: 'page_size') int pageSize,)?)

A variant of when that fallback to returning null

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function(@JsonKey(name: 'data')  List<UpdatedBook> updates,  int? total,  int page, @JsonKey(name: 'page_size')  int pageSize)?  $default,) {final _that = this;
switch (_that) {
case _UpdatedBookFeed() when $default != null:
return $default(_that.updates,_that.total,_that.page,_that.pageSize);case _:
  return null;

}
}