code: func promptUserAgreement(agreementURL string, changed bool) bool {
  	if changed {
  		fmt.Printf("The Let's Encrypt Subscriber Agreement has changed:\n  %s\n", agreementURL)
  		fmt.Print("Do you agree to the new terms? (y/n): ")
  	} else {
  		fmt.Printf("To continue, you must agree to the Let's Encrypt Subscriber Agreement:\n  %s\n", agreementURL)
  		fmt.Print("Do you agree to the terms? (y/n): ")
  	}
  
  	reader := bufio.NewReader(stdin)
  	answer, err := reader.ReadString('\n')
  	if err != nil {
  		return false
  	}
  	answer = strings.ToLower(strings.TrimSpace(answer))
  
  	return answer == "y" || answer == "yes"
  }
docs: // promptUserAgreement prompts the user to agree to the agreement
  // at agreementURL via stdin. If the agreement has changed, then pass
  // true as the second argument. If this is the user's first time
  // agreeing, pass false. It returns whether the user agreed or not.