https://blog.wongcw.com/2021/01/28/%e6%8d%b7%e8%b1%b9%e6%89%93%e9%80%a0%e5%85%a8%e6%96%b0c-type-continuation%ef%bc%9a%e5%b8%b6%e8%bb%8a%e8%bf%b7%e9%87%8d%e5%9b%9e%e9%bb%83%e9%87%91%e6%99%82%e4%bb%a3/