/**
     * Register handler names.
     * @param data The render data.
     */
    protected void registerHandlerNames(final RenderData data) {
        final String[] dataStoreNames = dataStoreFactory.getDataStoreNames();
        final List<Map<String, String>> itemList = new ArrayList<>();
        for (final String name : dataStoreNames) {
            final Map<String, String> map = new HashMap<>();