Fair point. In a true, classic Kay OO model the object is providing a well known interface to guard the mutation of the state. While I am definitely in the "pre

Fair point. In a true, classic Kay OO model the object is providing a well known interface to guard the mutation of the state. While I am definitely in the "prefer immutability" camp in the FP sense I'd argue that this push in the OO world is to cover up people's bad habits.