public function request(Request $request)
 {
     if ($this->requestsDelay) {
         usleep($this->requestsDelay);
     }
     $request->onComplete(array($this, 'notifyRequestIsComplete'));
     $this->requestsDefaults->applyToRequest($request);
     $request->setCookiesStorage($this->cookiesFilepath);
     if ($this->enableAutoReferer && $this->lastRequest) {
         $request->setCurlOption(CURLOPT_REFERER, $this->lastRequest->getUrl());
     }
     $this->mrHandler->pushRequestToQueue($request);
     if ($this->enableAutoStart) {
         $this->mrHandler->start();
     }
 }