错误＆＃34;通过守卫呼叫的推测性虚拟化＆＃34;，什么和为什么？

Question

我正在使用Xcode 9.4和Swift 4.1。但是，当我试图归档App Store构建的应用程序时。这是投掷和错误。

，这是第46行附近的代码

     override func viewDidLoad() {
        super.viewDidLoad()
        var attributes = [String: AnyObject]()
        attributes[NSForegroundColorAttributeName] = UIColor.red;

        self.setAndUpdateViewsData(self.kristal);


        self.lExpandableSummary.numberOfLines = 2;
        self.lExpandableSummary.collapsed = true;
        self.lExpandableSummary.collapsedAttributedLink = NSAttributedString(string: "show more", attributes: attributes);
        self.lExpandableSummary.expandedAttributedLink = NSAttributedString(string: "show less", attributes: attributes);
        self.lExpandableSummary.ellipsis = NSAttributedString(string: " ...");
//        self.lExpandableSummary.setLessLinkWith(lessLink: "show less", attributes: attributes, position: nil);

        self.lDesclaimer.numberOfLines = 2;
        self.lDesclaimer.collapsed = true;
        self.lDesclaimer.collapsedAttributedLink = NSAttributedString(string: "show more", attributes: attributes);
        self.lDesclaimer.expandedAttributedLink = NSAttributedString(string: "show less", attributes: attributes);
        self.lDesclaimer.ellipsis = NSAttributedString(string: " ...")
//        self.lDesclaimer.setLessLinkWith(lessLink: "show less",attributes: attributes, position: nil);


    }