I did not migrate `setProperty` either. My impression is that `anObject.setProperty("a.b.c.d", value)` is analogous to `anObject.a.b.c.d = value` except that it would silently short-circuit if any path component is null. Silently failing does not seem desirable to me on a `setProperty` method, but fine for the equivalent `aMontageObject.defineBinding("a.b.c.d", {"<-": "", source: aValue})` because the property will be set whenever and every time the path becomes complete.