Can someone explain how to contribute to this project if the public API diff test fails? I am new to this and would like to know what I am doing wrong.

The public API test is an approval test - it compares the generated file describing the current API against the previous one which is the "golden master" definition. The test is there so you can more easily review if there are any breaking changes introduced. If there are breaking changes then it means we should bump the major version number for the release. I haven't reviewed this PR but if you havent introduced any breaking api changes then there is nothing to worry about. To get the test to pass, copy the contents of the generated file in place of the contents of the current "golden master" file so that the next time the test runs it will compare the API surface to itself = pass.

Thanks for the explanation. Since there are no breaking changes, just an addition, should I fix the test and resubmit?

@bcwiniger - yep!

@bcwiniger Appologies for us taking so long to look at this. What is the use case for this property?

I think this is related to #257

@bcwiniger Please rebase onto master if you are still interested.