code: func (s *PresenceService) UpsertLocalClusterName(name string) error {
  	_, err := s.Put(context.TODO(), backend.Item{
  		Key:   backend.Key(localClusterPrefix, valPrefix),
  		Value: []byte(name),
  	})
  	return trace.Wrap(err)
  }
docs: // UpsertLocalClusterName upserts local cluster name