code: func (totp *TOTP) QRCodeData(label string) string {
  	// We need to URL Escape the label, but at the same time, spaces come through
  	// as +'s, so we need to reverse that encoding...
  	label = url.QueryEscape(label)
  	label = strings.Replace(label, "+", " ", -1)
  	return fmt.Sprintf("otpauth://totp/%v?secret=%v&Digits=%v&Period=%v", label, totp.Secret(), totp.Digits, totp.Period)
  }
docs: // Return the data to be contained in a QR Code for this TOTP with the given label.