public static function check(string $variableName = '_MF_SESSION_INTEGRITY_TOKEN_'): bool
    {
        static::init();
        $variableName = (string)$variableName;
        $vHandler = Variables::getInstance();
        $userToken = $vHandler->session->get($variableName, $vHandler::TYPE_STRING);
        $httpReferer = isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '';
        $rIntegrity = static::$refererIntegrityEnabled ? \stripos($httpReferer, static::$serverName) !== false : true;
        $tIntegrity = static::$tokenIntegrityEnabled ? $userToken === static::buildToken() : true;
        return $rIntegrity && $tIntegrity;
    }