https://blog.wongcw.com/2018/10/16/acme-cad-converter-2019-v8-9-8-1482-%e5%a4%9a%e8%af%ad%e8%a8%80%e4%b8%ad%e6%96%87%e6%b3%a8%e5%86%8c%e7%89%88%e9%99%84%e6%b3%a8%e5%86%8c%e7%a0%81/