public function isNewVisitor(): bool
    {
        $referer = System::getContainer()->get('request_stack')->getCurrentRequest()->headers->get('referer');
        $schemeAndHttpHost = System::getContainer()->get('request_stack')->getCurrentRequest()->getSchemeAndHttpHost();

        return null === $referer || false === preg_match('$^'.$schemeAndHttpHost.'$i', $referer);
    }