code: func callgrindName(names map[string]int, name string) string {
  	if name == "" {
  		return ""
  	}
  	if id, ok := names[name]; ok {
  		return fmt.Sprintf("(%d)", id)
  	}
  	id := len(names) + 1
  	names[name] = id
  	return fmt.Sprintf("(%d) %s", id, name)
  }
docs: // callgrindName implements the callgrind naming compression scheme.
  // For names not previously seen returns "(N) name", where N is a
  // unique index. For names previously seen returns "(N)" where N is
  // the index returned the first time.