数秒間、処理を待ちたい時 https://mogashiro.com/2021/06/27/%e6%95%b0%e7%a7%92%e9%96%93%e3%80%81%e5%87%a6%e7%90%86%e3%82%92%e5%be%85%e3%81%a1%e3%81%9f%e3%81%84%e6%99%82/