things you should know about contributing:

1.  API changes require discussion, use cases, etc. Code comes later.
2.  Pull requests are great for small fixes for bugs, documentation, etc.
3.  Pull requests are not merged directly into the master branch.
4.  Code contributions require signing a Google CLA.

API changes
-----------

To sign off a single commit:

`git commit --amend --signoff`

To sign off one or multiple commits:

`git rebase --signoff origin/master`

Then force push your branch:

`git push --force origin test-branch`

### Fixing sanity check failures after public API changes