private function processMessages()
    {
        while ($done = curl_multi_info_read($this->multiHandle)) {
            $request = $this->resourceHash[(int) $done['handle']];
            try {
                $this->processResponse($request, $this->handles[$request], $done);
                $this->successful[] = $request;
            } catch (\Exception $e) {
                $this->removeErroredRequest($request, $e);
            }
        }
    }