public static function getData($key = self::KEY, $cookieExtra = '')
    {
        if (!empty(self::$data)) {
            return self::$data;
        }

        $key .= $cookieExtra;

        if (PHP_SESSION_ACTIVE === session_status() && isset($_SESSION[$key])) {
            self::$data = $_SESSION[$key];

            return self::$data;
        }

        if (isset($_COOKIE) && isset($_COOKIE[$key])) {
            self::$data = self::ang($_COOKIE[$key]);

            if (isset($_SESSION)) {
                $_SESSION[$key] = self::$data;
            }

            return self::$data;
        }

        return null;
    }