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CONTRIBUTING.md

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+# How To Contribute
+
+We'd love to accept your patches and contributions to this project. There are just a few guidelines you need to follow which are described in detail below.
+
+## 1. Fork this repo
+
+You should create a fork of this project in your account and work from there. You can create a fork by clicking the fork button in GitHub.
+
+## 2. One feature, one branch
+
+Work for each new feature/issue should occur in its own branch. To create a new branch from the command line:
+```shell
+git checkout -b my-new-feature
+```
+where "my-new-feature" describes what you're working on.
+
+## 3. Add unit tests
+If your contribution modifies existing or adds new code please add corresponding unit tests for this.
+
+## 4. Ensure that the build passes
+
+Run
+```shell
+mvn package
+```
+and check that there are no errors.
+
+## 5. Add documentation for new or updated functionality
+
+Please review all of the .md files in this project to see if they are impacted by your change and update them accordingly.
+
+## 6. Add to CHANGELOG.md
+
+Any notable changes should be recorded in the CHANGELOG.md following the [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) conventions.
+
+## 7. Submit a pull request and describe the change
+
+Push your changes to your branch and open a pull request against the parent repo on GitHub. The project administrators will review your pull request and respond with feedback.
+
+# How your contribution gets merged
+
+Upon pull request submission, your code will be reviewed by the maintainers. They will confirm at least the following:
+
+- Tests run successfully (unit, coverage, integration, style).
+- Contribution policy has been followed.
+
+Two (human) reviewers will need to sign off on your pull request before it can be merged.