public function toString()
    {
        $request = sprintf('%s %s HTTP/%s', $this->getMethod(), (string) $this->getUrl(), $this->getVersion());

        $str = trim($request) . "\r\n";
        $str .= $this->getHeaders();
        $str .= "\r\n";
        $str .= $this->getContent();
        return $str;
    }