public static function extractDomain(RawRequest $rawRequest)
    {
        $domain = null;
        if (preg_match("/(?P<domain>[a-z0-9][a-z0-9\-]{1,63}\.[a-z\.]{2,6})$/i", $rawRequest->getHost(), $matches)) {
            $domain = $matches['domain'];
        }

        return $domain;
    }