code: func promAdjust(name string) string {
  	name = strings.Replace(name, "-", "_", -1)
  	name = strings.Replace(name, ".", "_", -1)
  	return invalidPromChars.ReplaceAllString(name, "")
  }
docs: // promAdjust adjusts a name for use by Prometheus: It and replaces "-" and "."
  // with "_". Invalid metric name characters that remain (e.g. `>`) are removed.