https://blog.wongcw.com/2018/12/21/%e8%98%8b%e6%9e%9c%e9%87%8d%e6%96%b0%e7%99%bc%e5%b8%83ios-12-1-2-%e5%8f%af%e8%83%bd%e4%bf%ae%e5%be%a9%e5%b0%8fbug/