public static function doesNeedRevalidation(string $variableName = '_MF_SESSION_REVALIDATED_AT_'): bool
    {
        static::init();
        $variableName = (string)$variableName;
        $vHandler = Variables::getInstance();
        $validationTS = $vHandler->session->get($variableName, $vHandler::TYPE_INT);
        return $validationTS < \time() - static::$revalidationTime ? true : false;
    }