https://blog.wongcw.com/2020/11/28/edge-canary%e6%96%b0%e7%89%b9%e6%80%a7%ef%bc%9a%e5%85%81%e8%a8%b1%e7%94%a8%e6%88%b6%e8%87%aa%e5%ae%9a%e7%be%a9%e7%aa%97%e5%8f%a3%e5%90%8d%e7%a8%b1/