function getExtensionArgs($request = null)
    {
        $args = array();

        if ($this->required) {
            $args['required'] = implode(',', $this->required);
        }

        if ($this->optional) {
            $args['optional'] = implode(',', $this->optional);
        }

        if ($this->policy_url) {
            $args['policy_url'] = $this->policy_url;
        }

        return $args;
    }