this is merged but i am sorry, I am not happy (in the sense not convinced) about this and I almost didn't keep track of the discussion on this since we digressed from testing modules to the "utility of modules" which was not the purpose of this PR.

This way of testing doesn't allow you to test the module in the context of the classes where you are including the module because you could very well test it like this and everything will be hunky and dory but it may still not be valid. Also modules / mixins in ruby are meant to be used as a way to implement multiple inheritance (barring the discussion whether someone hates it or loves it or the internals) and if all the behaviour in the module is not shared with all the classes it is included then conceptually it should not be a single module and this can only be tested using shared examples. Otherwise, it is far too easy to have one god module that is included in 3 classes where each of them use 1/3rd of the module behaviour which IMO is plain wrong. We can argue that "we don't/won't do that" but this way of testing doesn't restricts that.

Hence, I am not convinced and tilt towards `shared_examples`