We’ve all been there. We’ve got two (or more) classes with that have a need for the same functionality that share no base class. The project manager is asking when this will all be done, so we just create a method in one class and copy it over to the other. Then we find that another class has a need for the same functionality. So we copy it over to there as well…

I’d like to get this out of the way before I get into my thoughts on this - this is in no way a dig a Jimmy Bogard. He has provided a clear set of guidelines for the usage here. Unfortunately in my experience, many projects don’t follow these guidelines (and don’t get me wrong I’m guilty of violating some in the past myself).