https://blog.wongcw.com/2019/01/14/ressence%e6%8e%a8%e5%87%ba%e9%87%8f%e7%94%a2%e7%89%88type-2-e-crown%e8%85%95%e9%8c%b6%e5%94%ae4-25%e8%90%ac%e7%91%9e%e5%a3%ab%e6%b3%95%e9%83%8e/