private function readConnection(Request\TrackingRequest $request)
    {
        // response
        $response = '';

        // receive response
        do {
            $out = @socket_read($this->connection, self::READ_BUFFER);
            $response .= $out;

            if (!$out || strlen($out) < self::READ_BUFFER) {
                break;
            }
        } while (true);

        // response
        $responseContainer = explode("\r\n\r\n", $response, 2);
        return explode("\r\n", $responseContainer[0]);
    }