public function getPlaylistListFeed($user = null, $location = null)
    {
        if ($user !== null) {
            $uri = self::USER_URI . '/' . $user . '/playlists';
        } else if ($location instanceof Zend_Gdata_Query) {
            $uri = $location->getQueryUrl($this->getMajorProtocolVersion());
        } else {
            $uri = $location;
        }
        return parent::getFeed($uri, 'Zend_Gdata_YouTube_PlaylistListFeed');
    }