https://blog.wongcw.com/2019/03/08/ios-12-2-beta-4%e5%9b%ba%e4%bb%b6%e6%9b%9d%e5%85%89ipod-touch-7%ef%bc%9a5%e5%af%b8%e3%80%81%e7%84%a1%e5%8a%89%e6%b5%b7%e5%85%a8%e9%9d%a2%e5%b1%8f/