public function getCellFeed($location)
    {
        if ($location instanceof Zend_Gdata_Spreadsheets_CellQuery) {
            $uri = $location->getQueryUrl();
        } else if ($location instanceof Zend_Gdata_Spreadsheets_WorksheetEntry) {
            $uri = $location->getLink(self::CELL_FEED_LINK_URI)->href;
        } else {
            $uri = $location;
        }
        return parent::getFeed($uri, 'Zend_Gdata_Spreadsheets_CellFeed');
    }