づだ

<p><span class="embed-block zenn-embedded zenn-embedded-card"><iframe id="zenn-embedded__106c70f2efe44" src="https://embed.zenn.studio/card#zenn-embedded__106c70f2efe44" data-content="https%3A%2F%2Fdart.dev%2Fcodelabs%2Fasync-await" frameborder="0" scrolling="no" loading="lazy"></iframe></span><a href="https://dart.dev/codelabs/async-await" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://dart.dev/codelabs/async-await</a></p>


<p>Completer の complete に Future 渡して、Future が完了してないのに isCompleted が true になってたのをちゃんと調べる</p>
