asDocMeta().version(version);
    }

    @Override
    public Integer getTimeToLive() {
        String value = getHandlerParameterMap().get("time_to_live");
        if (StringUtil.isBlank(value)) {
            value = getHandlerParameterMap().get("timeToLive"); // TODO remove
            if (StringUtil.isBlank(value)) {
                return null;
            }

        final Map<String, String> paramEnvMap = systemHelper.getFilteredEnvMap(fessConfig.getCrawlerDataEnvParamKeyPattern());
        final Map<String, String> configParamMap = config.getHandlerParameterMap().entrySet().stream().map(e -> {
            final String key = e.getKey();
            String value = e.getValue();
            for (final Map.Entry<String, String> entry : paramEnvMap.entrySet()) {