absl::Span<const ops::NodeOut> values) {
  auto opts = builder.opts()
                  .WithName(std::move(name))
                  .WithAttr("dtypes", std::move(dtypes));
  if (opts.HaveError()) {
    return nullptr;
  }

  NodeBuilder node_builder(name, "Stage", opts.op_registry());
  node_builder.Input(values);
  return opts.FinalizeBuilder(&node_builder);
}

        if (loginCredential == null) {
            if (logger.isDebugEnabled()) {
                logger.debug("No user in SSO request.");
            }
            if (ssoManager.available()) {
                saveError(messages -> messages.addErrorsSsoLoginError(GLOBAL));
            }
            return redirect(LoginAction.class);
        }
        if (loginCredential instanceof ActionResponseCredential) {

        }
        if (doc == null) {
            saveError(messages -> messages.addErrorsDocidNotFound(GLOBAL, form.docId));
            return redirect(ErrorAction.class);
        }
        final String url = DocumentUtil.getValue(doc, fessConfig.getIndexFieldUrl(), String.class);
        if (url == null) {
            saveError(messages -> messages.addErrorsDocumentNotFound(GLOBAL, form.docId));

        }
        if (doc == null) {
            saveError(messages -> messages.addErrorsDocidNotFound(GLOBAL, form.docId));
            return redirect(ErrorAction.class);
        }

        final String content = viewHelper.createCacheContent(doc, form.hq);
        if (content == null) {
            saveError(messages -> messages.addErrorsDocidNotFound(GLOBAL, form.docId));

        final FessMessages messages = createMessages();
        validationMessagesLambda.message(messages);
        sessionManager.info().saveMessages(messages);
    }

    protected void saveError(final VaMessenger<FessMessages> validationMessagesLambda) {
        final FessMessages messages = createMessages();
        validationMessagesLambda.message(messages);
        sessionManager.errors().saveMessages(messages);