Google Drive API downloadFile getIo Error
===

I want to create a gDrive App.
I can get downloadUrl
(like as string 'https://doc-0k-68-docs.googleusercontent.com/docs/securesc/gf6salc3nfs5me1dnqgnp4crl90gg593/21kfelc8h3l1qvkgskqacnee2pqjt5es/1343484000000/14678698184812381901/14678698184812381901/0B95t2gVGbZ61Sk0yNlY5TTZObUU?h=16653014193614665626&e=download&gd=true' (length=251))

But i can't download via this link.
I guess, must some auth.

i try this functions, i take [here][1]


    function downloadFile($service, $file) {
      $downloadUrl = $file->getDownloadUrl();
      if ($downloadUrl) {
        $request = new apiHttpRequest($downloadUrl, 'GET', null, null);
        $httpRequest = $service->getIo()->authenticatedRequest($request);
        if ($httpRequest->getResponseHttpCode() == 200) {
          return $httpRequest->getResponseBody();
        } else {
          // An error occurred.
          return null;
        }
      } else {
        // The file doesn't have any content stored on Drive.
        return null;
      }
    }

i take an error 

   **Call to undefined method apiDriveService::getIo() in ....**

please help me. i can't found anywhere. 

  [1]: https://developers.google.com/drive/v1/reference/files/get