code: func locatorSummary(locator []*chainhash.Hash, stopHash *chainhash.Hash) string {
  	if len(locator) > 0 {
  		return fmt.Sprintf("locator %s, stop %s", locator[0], stopHash)
  	}
  
  	return fmt.Sprintf("no locator, stop %s", stopHash)
  
  }
docs: // locatorSummary returns a block locator as a human-readable string.