code: func isArchived(c context.Context, task *logdog.ArchiveTask) bool {
  	var err error
  	defer func() {
  		if err != nil {
  			logging.WithError(err).Errorf(c, "while checking if %s/%s is archived", task.Project, task.Id)
  		}
  	}()
  	if c, err = info.Namespace(c, "luci."+task.Project); err != nil {
  		return false
  	}
  	state := (&coordinator.LogStream{ID: coordinator.HashID(task.Id)}).State(c)
  	if err = datastore.Get(c, state); err != nil {
  		return false
  	}
  	return state.ArchivalState() == coordinator.ArchivedComplete
  }
docs: // checkArchived is a best-effort check to see if a task is archived.
  // If this fails, an error is logged, and it returns false.