public function index(Request $request, Response $response)
 {
     $helper = $this->helper;
     if ($helper->hasAccessToken()) {
         $client = new \GuzzleHttp\Client();
         $fileResponse = $client->get('https://www.googleapis.com/drive/v2/files', ['headers' => $helper->getAuthorizedHeaders()]);
         $files = new Files($fileResponse->getBody());
         return $this->view->render($response, 'files.twig', ['files' => $files->formatData(), 'area' => self::AREA]);
     } else {
         return $response->withStatus(301)->withHeader('Location', '/' . self::AREA . '/auth');
     }
 }