private function getUniqueUrl(NavItem $item)
 {
     $url = $item->getUrl();
     $action = $item->getAction();
     $params = $item->getParams();
     if (isset($action)) {
         $url = $url . '?' . self::$action . '=' . $action;
     }
     if (isset($params)) {
         $url = $url . '&' . self::$params . '=' . $params;
     }
     return $url;
 }