code: func identity() string {
  	hostname, err := os.Hostname()
  	h := sha1.New()
  	fmt.Fprint(h, hostname)
  	fmt.Fprint(h, err)
  	fmt.Fprint(h, os.Getpid())
  	return fmt.Sprintf("%x", h.Sum(nil))
  }
docs: // identity returns the same host/process unique string for the lifetime of
  // this process so that subscriber reconnections reuse the same queue name.