Good additional point that demands repetition: Don't mutate arguments to a (public) method if not absolutely necessary. Just to be clear, that does not make th

Good additional point that demands repetition: Don't mutate arguments to a (public) method if not absolutely necessary. Just to be clear, that does not make the approaches "incorrect". The list "names" is not necessarily an argument to a method. It might be a local, intermediate result that does not have the risk of "mutation at a distance".