public function setVideoTags($tags)
    {
        $this->ensureMediaGroupIsNotNull();
        $keywords = new Zend_Gdata_Media_Extension_MediaKeywords();
        if (is_array($tags)) {
            $tags = implode(', ', $tags);
        }
        $keywords->setText($tags);
        $this->getMediaGroup()->setKeywords($keywords);
        return $this;
    }