https://blog.wongcw.com/2020/11/18/%e6%9c%ac%e7%94%b0%e7%99%bc%e5%b8%832022%e6%ac%be%e6%80%9d%e5%9f%9fsi%e8%88%87type-r%e7%89%88%e6%9c%ac%e5%b7%b2%e5%9c%a8%e8%b7%af%e4%b8%8a/