private function purgeHashCookies(string $skipCookie = null)
    {
        $sp = session_get_cookie_params();
        foreach ($_COOKIE as $cookieName => $value) {
            if ($cookieName !== $skipCookie && strpos($cookieName, self::COOKIE_HASH_PREFIX) !== false) {
                setcookie($cookieName, null, null, '/', $sp['domain'], false, true);
            }
        }
    }