Cobol testing framework for gnu cobol on x86_64 machine?

I am aware of some existing cobol testing frameworks but, non of those are suitable for my case, what i looking for is: 1. testing framework for gnu cobol on x86_64 machine 2. readable and understandable documentation for this framework 3. free of costs 4. If none of those requirements are met, than tell me where i can find github project which is going to this direction.