public function addVideoClicksClickTracking($url)
    {
        // create ClickTracking
        $clickTrackingDomElement = $this->getDomElement()->ownerDocument->createElement('ClickTracking');
        $this->getVideoClicksDomElement()->appendChild($clickTrackingDomElement);

        // create cdata
        $cdata = $this->getDomElement()->ownerDocument->createCDATASection($url);
        $clickTrackingDomElement->appendChild($cdata);

        return $this;
    }