public function getMIMEType()
    {
        switch ($this->version) {
            case Feed::RSS2 : $mimeType = "application/rss+xml";
                break;
            case Feed::RSS1 : $mimeType = "application/rdf+xml";
                break;
            case Feed::ATOM : $mimeType = "application/atom+xml";
                break;
            default : $mimeType = "text/xml";
        }

        return $mimeType;
    }