We have a larger goal of replacing all DN creation via string formatting/concatenation with DN object operations because string operations are not a safe way to form a DN nor to compare a DN. This work needs to be broken into smaller chunks for easier review and testing.

Addressing the unit tests first makes sense because we don't want to be modifying both the core code and the tests used to verify the core code simultaneously. If we modify the unittests first with existing core code and no regressions are found then we can move on to modifying parts of the core code with the belief the unittests can validate the changes in the core code. Also by doing the unittests first we also help to validate the DN objects are working correctly (although they do have an extensive unittest).