function groups_pools_add ($photo_id, $group_id)
    {
        /** http://www.flickr.com/services/api/flickr.groups.pools.add.html */
        $this->request("flickr.groups.pools.add", array("photo_id"=>$photo_id, "group_id"=>$group_id), TRUE);
        return $this->parsed_response ? true : false;
    }