protected function refreshToken()
    {
        $token = $this->authorization->getApi()
                                     ->getAuthorizerToken(
                                         $this->authorization->getAuthorizerCorpId(),
                                         $this->authorization->getAuthorizerPermanentCode()
                                     );

        $this->authorization->setAuthorizerAccessToken($token['access_token'], $token['expires_in'] - 1500);

        return $token['access_token'];
    }