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CONTRIBUTING.md

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+# How to Contribute
+
+This project is published primarily as a (functional) tech demo. In case the
+project turns out to be useful for others, that’s great!
+
+Corrections and improvements to documentation are welcome. In general,
+corrections must pass the existing tests, and any changes which break the
+author’s use-case will be reverted.
+
+Please file an issue to get agreement on new features before sending a pull
+request. Simplicity is a core tenant of this project, so pull requests might be
+declined.
+
+## Contributor License Agreement
+
+Contributions to this project must be accompanied by a Contributor License
+Agreement. You (or your employer) retain the copyright to your contribution;
+this simply gives us permission to use and redistribute your contributions as
+part of the project. Head over to <https://cla.developers.google.com/> to see
+your current agreements on file or to sign a new one.
+
+You generally only need to submit a CLA once, so if you've already submitted one
+(even if it was for a different project), you probably don't need to do it
+again.
+
+## Code reviews
+
+All submissions, including submissions by project members, require review. We
+use GitHub pull requests for this purpose. Consult
+[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
+information on using pull requests.
+
+## Community Guidelines
+
+This project follows [Google's Open Source Community
+Guidelines](https://opensource.google.com/conduct/).