[Pharo-dev] hash and Collections

Hi, Can anyone explain me how this is correct? Collection>>#hash "Answer an integer hash value for the receiver such that, -- the hash value of an unchanged object is constant over time, and -- two equal objects have equal hash values" | hash | hash := self species hash. self size <= 10 ifTrue: [self do: [:elem | hash := hash bitXor: elem hash]]. ^hash bitXor: self size hash I mean… a hash that changes when I add elements to the collection… how can this work? Esteban