The comment example in SpaceTally>>systemWideSpaceTally:
    "(SpaceTally new systemWideSpaceTally asSortedCollection: [:a :b | a
last > b last]) asArray"
will cause a "MessageNotUnderstood: SpaceTallyItem>>last" (after 5 minutes
or so).

#last is probably supposed to be #spaceForInstances.

Eddie