final String attrPager = fessConfig.getLdapAttrPager();
        OptionalUtil.ofNullable(user.getPager())
                .filter(StringUtil::isNotBlank)
                .ifPresent(s -> modifyReplaceEntry(modifyList, attrPager, s))

            this.closed = false;
        }

        boolean isAlive() {
            return resourceRef.get() != null && !closed;
        }

        long getAge() {
            return System.currentTimeMillis() - creationTime;
        }
    }

    private ResourceManager() {
        ThreadFactory threadFactory = r -> {