you probably misunderstood what I did. In fact, I propose a
completely new persistency model that has nothing to do with
PRImagePersistency (mine is called PRSaveImagePersistency).
This persistency layer saves the image every time the model
is modified.
It doesn't manage concurrence nor recovering after a bad snapshot.
No, I understood what you were doing, you misunderstand what my suggestion
offers. With your save image persister, if you use the do and reverseDo I
suggest, the change and history views for a page will work, which they
currently don't.