*Replace this paragraph with a description of what this PR is changing or adding, and why. Consider including before/after screenshots.*

*List which issues are fixed by this PR. For larger changes, raising an issue first helps
reduce redundant work.*

## Pre-launch Checklist

- [ ] I read the [Effective Dart: Style] _recently_, and have followed its advice.
- [ ] I signed the [CLA].
- [ ] I updated/added relevant documentation (doc comments with `///`).
- [ ] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-devrel channel on [Discord].

<!-- Links -->
[Effective Dart: Style]: https://dart.dev/guides/language/effective-dart/style
[CLA]: https://cla.developers.google.com/
[Discord]: https://github.com/flutter/flutter/blob/master/docs/contributing/Chat.md
