final FessConfig fessConfig = ComponentUtil.getFessConfig();
        @SuppressWarnings("unchecked")
        final Map<String, Object> source = obj instanceof Map ? (Map<String, Object>) obj : BeanUtil.copyBeanToNewMap(obj);
        final String id = (String) source.remove(fessConfig.getIndexFieldId());
        source.remove(fessConfig.getIndexFieldVersion());