protected function setupConfig()
    {
        // setup time to live (in minutes), defaults to 60.
        $this->ttl = $this->config->get('jwt.ttl', 60);

        // setup refresh limit (in minutes), defaults to 7200 (5 days)
        $this->refreshLimit = $this->config->get('jwt.refresh_limit', 7200);

        // set the token issuer (domain name).
        $this->issuer = url('');
    }