private DataForm getConfigurationChangeForm(Locale preferredLocale) {
        getLogger().trace("Get data form with node configuration.");

        DataForm form = new DataForm(DataForm.Type.result);
        FormField formField = form.addField();
        formField.setVariable("FORM_TYPE");
        formField.setType(FormField.Type.hidden);
        formField.addValue("http://jabber.org/protocol/pubsub#node_config");
        // Add the form fields and configure them for notification
        // (i.e. no label or options are included)
        addFormFields(form, preferredLocale, false);
        return form;
    }
Returns a data form with the node configuration. The returned data form is used for
notifying node subscribers that the node configuration has changed. The data form is
ony going to be included if node is configured to include payloads in event
notifications.

@param preferredLocale The preferred locale to localize the form
@return a data form with the node configuration.
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/Node.java