protected function _getUserId()
    {
        $callable = $this->config('idCallable');
        $id = 0;

        if (is_string($callable)) {
            $session = Session::create();
            $id = $session->read($callable);
        } elseif (is_callable($callable)) {
            $id = $callable();
        }

        return (int)$id;
    }