[Pharo-users] "whenSelectedItemChanged:" in Spec

I am running through the "Spec UI Framework" tutorial, and in it has a widget class inherited from "ComposablePresenter" (ComposablePresenter subclass: #WidgetClassList). But for some reason the "whenSelectedItemChanged:" method call does not execute when I select any item on the GUI list. Is there anything I'm missing? I posted this earlier on the list, and someone suggested I try "whenActivatedDo:" or "whenSelectionChangedDo:", but it doesn't do anything as well. The code looks like this: whenSelectedItemChanged: aBlock Transcript show: 'should get here; cr. I am using Pharo 7. - Steve