public function getNicknameFeed($location = null)
    {
        if ($location === null) {
            $uri = $this->getBaseUrl() . self::APPS_NICKNAME_PATH;
        } else if ($location instanceof Zend_Gdata_Query) {
            $uri = $location->getQueryUrl();
        } else {
            $uri = $location;
        }
        return parent::getFeed($uri, 'Zend_Gdata_Gapps_NicknameFeed');
    }