Pull requests without a rationale and clear improvement may be closed
immediately.

Please provide clear motivation for your patch and explain how it improves
Dash Core user experience or Dash Core developer experience
significantly.

* Any test improvements or new tests that improve coverage are always welcome.
* All other changes should have accompanying unit tests (see `src/test/`) or
  functional tests (see `test/`). Contributors should note which tests cover
  modified code. If no tests exist for a region of modified code, new tests
  should accompany the change.
* Bug fixes are most welcome when they come with steps to reproduce or an
  explanation of the potential issue as well as reasoning for the way the bug
  was fixed.
* Features are welcome, but might be rejected due to design or scope issues.
  If a feature is based on a lot of dependencies, contributors should first
  consider building the system outside of Dash Core, if possible.