Frontend\Core\Engine\Url::getQueryString PHP Method

    public function getQueryString()
    {
        return rtrim((string) $this->request->getRequestUri(), '/');
    }

 /**
  * Get the id of an item by the full URL of the current page.
  * Selects the proper part of the full URL to get the item's id from the database.
  *
  * @param FrontendURL $URL The current URL.
  * @return int
  */
 public static function getIdForTags(FrontendURL $URL)
 {
     return FrontendNavigation::getPageId($URL->getQueryString());
 }