public function __construct($data = null)
{
$this->add(self::GOOGLE_ID, 'Google', 'http://www.google.com/webmasters/sitemaps/ping?sitemap=')->add(self::YAHOO_ID, 'Yahoo', 'http://search.yahooapis.com/SiteExplorerService/V1/updateNotification?appid=SitemapWriter&url=')->add(self::BING_ID, 'Bing', 'http://www.bing.com/webmaster/ping.aspx?siteMap=');
parent::__construct($data);
}
