/**
     * The Fess configuration.
     */
    protected FessConfig fessConfig;

    /**
     * The data serializer.
     */
    protected DataSerializer dataSerializer;

    /**
     * Get the extractor.
     * @param responseData The response data.
     * @return The extractor.
     */
    protected abstract Extractor getExtractor(ResponseData responseData);

                if (data != null) {
                    try {
                        final DataSerializer dataSerializer = ComponentUtil.getComponent("dataSerializer");
                        @SuppressWarnings("unchecked")
                        final Map<String, Object> responseDataMap = (Map<String, Object>) dataSerializer.fromBinaryToObject(data);
                        return responseDataMap;

                            try {
                                final DataSerializer dataSerializer = ComponentUtil.getComponent("dataSerializer");
                                @SuppressWarnings("unchecked")
                                final Map<String, Object> responseDataMap = (Map<String, Object>) dataSerializer.fromBinaryToObject(data);
                                mergeResponseData(dataMap, responseDataMap);