Fixed the converter not keeping and using reference of objects with no dependencies

The issue discussed earlier where an object was created more then once when used as a dependency for another object was (also?) happening on objects that had no dependencies. This here is a fix to that problem with the required modifications to the tests.

I changed the tests so that the mock expectations don't fail after those modifications. I also added a second call to the function with the same parameters, plus an assertion (`assertSame(...)`) to ensure both calls return exactly the same object (same reference) instead of an equal but yet different object.