2. All contributions must be licensed Apache 2.0 and all files must have a
     copy of the boilerplate license comment (can be copied from an existing
     file).
  3. Files should be formatted according to Google's [Java style guide][].
  4. Please squash all commits for a change into a single commit (this can be
     done using `git rebase -i`). Do your best to have a
     [well-formed commit message][] for the change.

For any non-trivial change, we need to be able to answer these questions:

* Why is this change done? What's the use case?
* For user facing features, what will the API look like?
* What test cases should it have? What could go wrong?
* How will it roughly be implemented? We'll happily provide code pointers to save you time.

***NOTE***: Only original source code from you and other people that have signed the CLA can be accepted into the main repository.

### Contributing code

If you have improvements to TensorFlow, send us your pull requests! For those
just getting started, GitHub has a
[how-to](https://help.github.com/articles/using-pull-requests/).