public static function add(/** polymorphic **/)
    {
       $args = func_get_args();
       $that = self::get_this($args);
       $term = self::get_term($args);

       $url = URIResource::Make($that->path, array($that->id, $term));

       $id = Locator::Find($that->client->post($url, $args->get()));
        
       return $this->$term($id);
    }