[WIP] Re-verifier

[renkelvin]

Hey there! So you want to contribute to a Firebase SDK? Before you file this pull request, please read these guidelines:

Discussion

• Read the contribution guidelines (CONTRIBUTING.md).
• If this has been discussed in an issue, make sure to link to the issue here. If not, go file an issue about this before creating a pull request to discuss.

Testing

• Make sure all existing tests in the repository pass after your change.
• If you fixed a bug or added a feature, add a new test to cover your code.

API Changes

• At this time we cannot accept changes that affect the public API. If you'd like to help us make Firebase APIs better, please propose your change in a feature request so that we can discuss it together.

[google-oss-bot]

	1 Warning
:warning:	Did you forget to add a changelog entry? (Add #no-changelog to the PR description to silence this warning.)

Generated by :no_entry_sign: Danger