https://blog.wongcw.com/2020/08/22/php-8-beta-2-%e7%99%bc%e5%b8%83%ef%bc%8c%e4%bf%ae%e5%be%a9%e4%b8%80%e5%80%8b%e5%85%a7%e5%ad%98%e6%b4%a9%e6%bc%8fbug/