code: func reset(s Store) (bool, error) {
  	assigned, err := s.Assigned()
  	if err != nil {
  		return false, err
  	}
  	if err := s.SetLastKnownGood(nil); err != nil {
  		return false, fmt.Errorf("failed to reset last-known-good UID in checkpoint store, error: %v", err)
  	}
  	if err := s.SetAssigned(nil); err != nil {
  		return false, fmt.Errorf("failed to reset assigned UID in checkpoint store, error: %v", err)
  	}
  	return assigned != nil, nil
  }
docs: // reset is a helper for implementing Reset, which can be implemented in terms of Store methods