Cancelling a Session Save

Hi all -
I’m wondering if there is a hook for cancelling the save session while you are in a callback for the before-session-write event. I don’t need to cancel in a real situation, but while debugging I’d like to be able to, as rv is hanging during the session write process somewhere, and it would be nice to be able to exit before it starts hanging.

Is there something kind of analogous to changing an incoming source path using event.setReturnContent(new_path) in the incoming-source-path event callback?