public function serializeToXml()
    {
        $xml = new \SimpleXMLElement('<?xml version="1.0" encoding="utf-8"?><RefererConfiguration></RefererConfiguration>');
        if ($this->allowEmptyReferer) {
            $xml->addChild('AllowEmptyReferer', 'true');
        } else {
            $xml->addChild('AllowEmptyReferer', 'false');
        }
        $refererList = $xml->addChild('RefererList');
        foreach ($this->refererList as $referer) {
            $refererList->addChild('Referer', $referer);
        }
        return $xml->asXML();
    }