public function acquireItem($key, $index = false)
    {
        if ($index === self::INDEX_KEY) {
            $nb_site = CNabuEngine::getEngine()->getApplication()->getRequest()->getSite();
            $retval = CNabuSiteTarget::findByKey($nb_site, $key);
        } else {
            $retval = parent::acquireItem($key, $index);
        }

        return $retval;
    }