sequence on model has wrong type

When I create a document everything works fine. But when I load a model, then I get the following error: "type String is not a sub type of int" which totaly make sense. But in the lib the code is like the following:

/// Document automatically incrementing ID. final int $sequence;

factory Document.fromMap(Map<String, dynamic> map) { return Document( $id: map['id'].toString(), $sequence: map['sequence'], $collectionId: map['collectionId'].toString(), $databaseId: map['databaseId'].toString(), $createdAt: map['createdAt'].toString(), $updatedAt: map['updatedAt'].toString(), $permissions: List.from(map['permissions'] ?? []), data: map, );

and is receives map['sequence'], as "1" for example. So it is a String and is cannot converted to an in on the fromMap method.