Currently, we expect instance_type_id to be an integer, but we store it in the database as a char field. I'd like to keep it that way as I've heard we may start using alphanumeric instance_types. Since we store it as a char field, this will always fail. Perhaps, the is_int should first check it's it's actually an int. Then, if it's not, it'll attempt to cast it to an int, and if it can, it still passes.