https://blog.wongcw.com/2022/07/14/%e6%80%9d%e5%9f%9ftype-r%e5%ae%98%e5%9c%96%e6%b4%a9%e9%9c%b2%ef%bc%9a%e6%9c%ac%e7%94%b0%e6%9c%80%e5%bc%b7%e8%b2%b7%e8%8f%9c%e8%bb%8a%e5%94%ae%e5%83%b9%e7%b4%8427%e8%90%ac%e5%85%83/