public function batchUpdate($documentId, Google_Service_Docs_BatchUpdateDocumentRequest $postBody, $optParams = array())
  {
    $params = array('documentId' => $documentId, 'postBody' => $postBody);
    $params = array_merge($params, $optParams);
    return $this->call('batchUpdate', array($params), "Google_Service_Docs_BatchUpdateDocumentResponse");
  }