code: def find_old_vidyo_rooms(max_room_event_age):
      
      recently_used = (db.session.query(VCRoom.id)
                       .filter(VCRoom.type == 'vidyo',
                               Event.end_dt > (now_utc() - timedelta(days=max_room_event_age)))
                       .join(VCRoom.events)
                       .join(VCRoomEventAssociation.event)
                       .group_by(VCRoom.id))
  
      # non-deleted rooms with no recent associations
      return VCRoom.find_all(VCRoom.status != VCRoomStatus.deleted, ~VCRoom.id.in_(recently_used))
docs: Finds all Vidyo rooms that are:
         - linked to no events
         - linked only to events whose start date precedes today - max_room_event_age days