I think this is more based on the early methodology advice for developing OO software. But the methodology is independent of the constructs (though often limite

I think this is more based on the early methodology advice for developing OO software. But the methodology is independent of the constructs (though often limited by it). In practice these days often the most effective way when developing OO code is working the "proofs" till you have a set of classes. Also, some people go for very FP inspired OO code.