protected function sendMultiple(array $requests)
    {
        $curlMulti = $this->getCurlMulti();
        foreach ($requests as $request) {
            $curlMulti->add($request);
        }
        $curlMulti->send();

        /** @var $request RequestInterface */
        $result = array();
        foreach ($requests as $request) {
            $result[] = $request->getResponse();
        }

        return $result;
    }