code: func (al AnnounceList) OverridesAnnounce(announce string) bool {
  	for _, tier := range al {
  		for _, url := range tier {
  			if url != "" || announce == "" {
  				return true
  			}
  		}
  	}
  	return false
  }
docs: // Whether the AnnounceList should be preferred over a single URL announce.