https://blog.wongcw.com/2022/10/12/%e6%9c%80%e5%bc%b7%e6%9c%ac%e7%94%b0%e6%80%9d%e5%9f%9f%e7%99%bb%e5%a0%b4type-r%e4%b8%ad%e6%96%87%e5%90%8d%e5%8f%ab%e9%a6%ad%e5%86%a0/