Collect on IdentitySet

Hey All,

The collect: on IdentitySet returns Set. Is this really wanted behaviour or is it a bug?

For example:

set := IdentitySet with: 'foo' with: 'bar'.
newSet := set collect: [:e | #size -> e size   ].

This two assertions do not pass:
self assert: newSet size == 2.
self assert: newSet class == IdentitySet

Surprisingly (for me), if I change the implementation of collect: to use
self species new instead of: Set new, the Pharo becomes really unresponsive...

Cheers, Jan