public function validate(int $uuid, int $expecting_type_id = null): int
    {
        if ($uuid < 1 || $uuid > 9223372036854775807) {
            throw $this->c::issue('UUID64 out of range.');
        }
        if (isset($expecting_type_id)) {
            $this->typeIdIn($uuid, $expecting_type_id);
        }
        return $uuid;
    }