code: func PrefixedUniqueId(prefix string) string {
  	// Be precise to 4 digits of fractional seconds, but remove the dot before the
  	// fractional seconds.
  	timestamp := strings.Replace(
  		time.Now().UTC().Format("20060102150405.0000"), ".", "", 1)
  
  	idMutex.Lock()
  	defer idMutex.Unlock()
  	idCounter++
  	return fmt.Sprintf("%s%s%08x", prefix, timestamp, idCounter)
  }
docs: // Helper for a resource to generate a unique identifier w/ given prefix
  //
  // After the prefix, the ID consists of an incrementing 26 digit value (to match
  // previous timestamp output).  After the prefix, the ID consists of a timestamp
  // and an incrementing 8 hex digit value The timestamp means that multiple IDs
  // created with the same prefix will sort in the order of their creation, even
  // across multiple terraform executions, as long as the clock is not turned back
  // between calls, and as long as any given terraform execution generates fewer
  // than 4 billion IDs.