private function storeAccessTokenInSession(\OAuth2\ResponseInterface $response)
 {
     $location = $response->getHttpHeader('Location');
     $parsed = parse_url($location);
     if (isset($parsed['fragment'])) {
         $fragment = $parsed['fragment'];
     } else {
         $fragment = $parsed['query'];
     }
     parse_str($fragment, $attributes);
     if (isset($attributes['access_token'])) {
         //$_SESSION['oauth2_access_token'] = $attributes['access_token'];
         Application::getInstance()->getRouter()->getRequest()->getSession()->set('oauth2_access_token', $attributes['access_token']);
     }
 }