code: func SortByRevision(list []*rspb.Release) {
  	s := &sorter{list: list}
  	s.less = func(i, j int) bool {
  		vi := s.list[i].Version
  		vj := s.list[j].Version
  		return vi < vj
  	}
  	sort.Sort(s)
  }
docs: // SortByRevision returns the list of releases sorted by a
  // release's revision number (release.Version).