code: func (s Shard) Serialize() []byte {
  	sorted := make([]string, 0, len(s))
  	for blob := range s {
  		sorted = append(sorted, blob)
  	}
  	sort.Strings(sorted)
  	out := bytes.Buffer{}
  	enc := gob.NewEncoder(&out)
  	err := enc.Encode(sorted)
  	if err != nil {
  		panic("impossible error when encoding []string")
  	}
  	return out.Bytes()
  }
docs: // Serialize serializes the shard to a byte buffer.