code: def get_last_update(op):
    
    last_update = get_end_time(op)
  
    if not last_update:
      last_event = get_last_event(op)
      if last_event:
        last_update = last_event['timestamp']
  
    if not last_update:
      last_update = get_create_time(op)
  
    return last_update
docs: Return the most recent timestamp in the operation.