How can I save an empty bundle?

[ofseed]

I am using overseer with a session manager and found that the function
save_task_bundle only actually saves tasks when there are tasks.

Therefore, if I dispose all the tasks and exit, execute save_task_bundle automatically which does nothing.
Next time I load this session again, it will load the tasks I already disposed of.

I want to save an empty bundle when I disposed of all tasks
so that these tasks will not load again when I load this session,
what should I do?

[stevearc]

This was an oversight in the bundle saving logic. I've pushed up a change; it should work as expected now