@Override
  public void validate(W webModel, M serviceModel) {
    assertError(
        webModel.isNotifyUsers() && !webModel.isCreateUsers(),
        "Notify users flag does not make sense unless create user flag is set");
    assertError(
        webModel.isCreateUsers() && !userHelper.canAddUsers(),
        "Create users flag does not make sense unless writable user directory is configured or number of already registered users increased.");

    serviceModel.setCreateUsers(webModel.isCreateUsers());
    serviceModel.setNotifyUsers(webModel.isNotifyUsers());
    serviceModel.setCcAssignee(webModel.isCcAssignee());
    serviceModel.setCcWatcher(webModel.isCcWatcher());
    serviceModel.setStripQuotes(webModel.isStripQuotes());
  }