code: func shortID() string {
  	b := make([]byte, 6)
  	io.ReadFull(rand.Reader, b)
  	return base64.StdEncoding.EncodeToString(b)
  }
docs: // shortID produces a "unique" 6 bytes long string.
  // Do not use as a reliable way to get unique IDs, instead use for things like logging.