Nested operations

[avariant]

I think I know the answer, and the answer is no, but I figured I'd check.
Can you nest start_operation, commit_operation calls? For example:

model.start_operation "Operation A"
#do something
model.start_operation "Operation B"
#do some more stuff
model.commit_operation  #ending operation B
#do some final stuff
model.commit_operation  #ending operation A

I figure the answer is that it at least won't work the way I want. What I would expect is that the outermost start / commit (Operation A), would be the only one exposed in the Undo / Redo because it contains Operation B within it. But what I think I see is that both A and B show up in the menu. This seems bad, because it implies that some operations from A are either being attributed to B, or being handled outside all the operations entirely. Anyway, does anyone know a more official explanation? The API, as usual, says very little on the subject.

[todd burch]

No, you cannot do nest commits. Assume the behavior is undefined.

[avariant]

Ok. thanks!