* @param mediaType the media type for the content builder
     * @return an OutputStream containing the built content, or an empty ByteArrayOutputStream if an error occurs
     */
    public static OutputStream getXContentBuilderOutputStream(final XContentBuilderCallback func, final MediaType mediaType) {
        try (final XContentBuilder builder = func.apply(mediaType.contentBuilder(), ToXContent.EMPTY_PARAMS)) {
            builder.flush();

        clusterStatus = response.getStatus().toString();
        final Set<String> fieldSet = ComponentUtil.getFessConfig().getApiPingEsFieldSet();
        try (OutputStream out = SearchEngineUtil.getXContentBuilderOutputStream((builder, params) -> {
            builder.startObject();
            if (fieldSet.contains(CLUSTER_NAME)) {
                builder.field(CLUSTER_NAME, response.getClusterName());
            }