private void validateCustomerEmail(String customerEmail) throws InvalidSeatHoldRequestException {
    if (customerEmail == null || customerEmail.isEmpty()) {
      throw new InvalidSeatHoldRequestException("Customer email cannot be null or empty");
    }

    if (!emailValidator.isValid(customerEmail, null)) {
      throw new InvalidSeatHoldRequestException(
          String.format("%s is not a valid email address", customerEmail));
    }
  }
  /**
   * Fails if both the input field for manual email address input is empty and there is no csv file
   * with content
   */
  @Override
  public void validate(Object target, Errors errors) {
    InvitationForm form = (InvitationForm) target;

    if (StringUtils.hasText(form.getEmails())) {
      String[] emails = form.getEmails().split(",");
      for (String email : emails) {
        if (!EMAIL_VALIDATOR.isValid(email.trim(), null)) {
          errors.rejectValue("emails", "error.WrongFormattedEmailList");
          break;
        }
      }
    }

    if (form.hasCsvFile() && form.getCsvFile().isEmpty()) {
      errors.rejectValue("csvFile", "invite.errors.EmptyCSV");
    }

    if (!StringUtils.hasText(form.getEmails()) && !form.hasCsvFile()) {
      errors.rejectValue("emails", "invite.errors.NoEmailAddresses");
    }
  }