@aleix , our companion object implements some interface which we want to mock (e.g. return results configurated by test case).
Problem with "final" classes may be fixed by different ways ("all-open" gradle plugin, PowerMock, MockMaker from Mockito2 (
http://hadihariri.com/2016/10/04/Mocking-Kotlin-With-Mockito/)), but I don't understand how to annotate companion object to make it mockable with one of those approaches.