Newscoop\NewscoopBundle\Security\Http\Authentication\AbstractAuthenticationHandler::extractDomain PHP Method

    private function extractDomain($domain)
    {
        if (preg_match("/(?P<domain>[a-z0-9][a-z0-9\\-]{1,63}\\.[a-z\\.]{2,6})\$/i", $domain, $matches)) {
            return $matches['domain'];
        } else {
            return $domain;
        }
    }