final XContentBuilder builder = XContentFactory.jsonBuilder();
            builder.startObject();
            response.toXContent(builder, ToXContent.EMPTY_PARAMS);
            builder.endObject();
            builder.flush();
            try (OutputStream out = builder.getOutputStream()) {
                stats = ((ByteArrayOutputStream) out).toString(Constants.UTF_8);
            }

            }
            if (fieldSet.contains(ACTIVE_SHARDS_PERCENT_AS_NUMBER)) {
                builder.field(ACTIVE_SHARDS_PERCENT_AS_NUMBER, response.getActiveShardsPercent());
            }
            builder.endObject();
            return builder;
        }, XContentType.JSON)) {
            message = ((ByteArrayOutputStream) out).toString(Constants.UTF_8);
            if (StringUtil.isBlank(message)) {

        if (activeFeatures != null && !activeFeatures.isEmpty()) {
            builder.field(ACTIVE_FEATURES.getPreferredName(), activeFeatures);
        }
        printBoostAndQueryName(builder);
        builder.endObject();
    }

    @Override
    protected Query doToQuery(final QueryShardContext context) throws IOException {
        throw new UnsupportedOperationException("Query processing is not supported.");
    }