https://blog.wongcw.com/2020/04/01/edge-canary%e8%b7%9f%e9%80%b2%ef%bc%9a%e5%85%81%e8%a8%b1%e7%94%a8%e6%88%b6%e8%87%aa%e5%ae%9a%e7%be%a9%e4%b8%8a%e5%82%b3%e6%96%b0%e6%a8%99%e7%b1%a4%e9%a0%81%e5%a3%81%e7%b4%99/