provide full coverage for core module

Of course not totally full coverage (for example don't make sense to test log statements).
Achieve this with pure unit testing and use of opportune mocking to test ironjacamar's code is correct, assuming that provided libs are correct (for example tx subsystem)
As pure unit test we will test single behavior of a class assuming that other ironjacamarr's classes re correct too (the corectness is proven in this case by other unit tests)