I get what he is talking about, but to be honest alI never encountered a situation where I intentionally or unintentionally got to diamond inheritance. I just d

I get what he is talking about, but to be honest alI never encountered a situation where I intentionally or unintentionally got to diamond inheritance. I just didn't... As for the add/addAll example, the smart thing to do is just not put too much in the public method or just declare it final...