code: func (s *Storage) ListDeleted() ([]*rspb.Release, error) {
  	s.Log("listing deleted releases in storage")
  	return s.Driver.List(func(rls *rspb.Release) bool {
  		return relutil.StatusFilter(rspb.Status_DELETED).Check(rls)
  	})
  }
docs: // ListDeleted returns all releases with Status == DELETED. An error is returned
  // if the storage backend fails to retrieve the releases.