self withContextDo:  - is called in #buildChildren and in all of
the methods #buildChildren calls
or is being up all night getting to me?
You are right. Removing the unnecessary #withContextDo: calls will
make the code a bit faster ;-)
also, how about:
self value ifNotNilDo: [ :fileModel | fileModel delete ].
self value: nil
(and at least a dummy #delete method on MAFileModel)
for those file models which handle removal.
Ok, I added that to the latest version. I called it #finalize,
because the deletion is (in my opinion) on a different level of
abstraction. This is rather a cleanup that is done (as opposed to the