//  expires
        if (documentExpires != null) {
            defaultDataMap.put(fessConfig.getIndexFieldExpires(), documentExpires);
        }
        // segment
        defaultDataMap.put(fessConfig.getIndexFieldSegment(), initParamMap.getAsString(Constants.SESSION_ID));
        // created
        defaultDataMap.put(fessConfig.getIndexFieldCreated(), systemHelper.getCurrentTime());
        // boost