sharing a note, allow editing, back up note to recover from accidental delete.

This is the situation. I shared a note file, fifty notes long with at least five people, all were permitted to edit. I did not access for months, however when I went to this note file, only one note of the fifty still existed, all other notes were gone.

Apple care went through the basics, without success. Apple care suggested that whoever deleted it might be able to restore it. Unable to verify who deleted, as such, I was unable to recover the note, fortunately it was a non critical note.

This raises the question, how can I back up a shared note to recover it if a shared user happens to delete content by accident or design?