This youtube video describes a tool for unit testing (and not only) of flow services. At about 24:00 they tell about the code coverage capabilities which are quite impressive.
I’d like to know how is it possible to obtain code coverage stats of an execution of a flow service. Is there some API in the IS which can be plugged into? Is some document published on execution of each and every flow step? Or does one have to somehow instrument the IS code to obtain it (like many java tools do)?