Does NSPasteboard retain owner objects?

Question

You can call NSPasteboard like this:

[pboard declareTypes:types owner:self];

Which means that the pasteboard will later ask the owner to supply data for a type as needed. However, what I can't find from the docs (and maybe I've missed something bleeding obvious), is whether or not owner is retained.

In practice what's worrying me is if the owner is a weak reference, it could be deallocated, causing a crash if the pasteboard then tries to request data from it.

Note: I should probably clarify that I'm interested in this more as an aid to tracking down a bug, than making my app rely on it. But I do also want the docs clarified.