final Map<String, Object> source = toLowerHyphen(searchLogEvent.toSource());
        source.put("_id", searchLogEvent.getId());
        // source.put("version_no", searchLogEvent.getVersionNo());
        source.put("event_type", searchLogEvent.getEventType());
        return source;
    }

    /**
     * Converts a map to lower hyphen case.
     *