public function is_null(string $name, int $type = null): bool
    {
        if (isset(self::$globalOptions[$name]) && (is_null($type) || $type == self::TYPE_GLOBAL)) {
            return is_null(self::$globalOptions[$name]);
        } else {
            if (isset($this->options[$name]) && (is_null($type) || $type == self::TYPE_LOCAL)) {
                return is_null($this->options[$name]);
            } else {
                return true;
            }
        }
    }