The PureMVC Framework Code at the Speed of Thought

When looking at this, it makes sense and is a nice way of 'short circuiting'? the framework for unit testing. The only thing I got hung up on is
// Manually register an observer on this proxy for the specified notification.
view.registerObserver(notificationName, new Observer(handler, this)); }
Larry admits this is not very clean. I'm not sure this can be done any other way. It seems registerObserver is only defined on IView. Is there in fact some other mechanism by which to register an Observer ? I'm guessing no.

Thanks.