[Pharo-users] Is it always needed to redefine #hash message when you redefine #= message?

The subject of this mail is exactly my question. I came to this question by looking at Object>>#= message implementation. """ = anObject "Answer whether the receiver and the argument represent the same object. If = is redefined in any subclass, consider also redefining the message hash." ^self == anObject """ When do we need to redefine #hash message? Is it the right way to implement equality between two objects or is there another message that I should override? Regards, Julien