if (singleton == null) {
            synchronized (HttpUtil.class) {
                if (singleton == null) {                    singleton = new OkHttpClient.Builder()
                            .connectTimeout(10, TimeUnit.SECONDS)
                            .readTimeout(20, TimeUnit.SECONDS)
                            .addInterceptor(new LoggingInterceptor())
                            .cookieJar(new CookieJar() {
                                private final HashMap<String, List<Cookie>> cookieStore = new HashMap<>();                                @Override
                                public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {                                    cookieStore.put(url.host(), cookies);                                }                                @Override
                                public List<Cookie> loadForRequest(HttpUrl url) {
                                    List<Cookie> cookies = cookieStore.get(url.host());
                                    System.out.println("Cookies======="+cookies);
                                    return cookies != null ? cookies : new ArrayList<Cookie>();
                                }
                            }).build();
                }
            }
        }
debug时代码运行到 cookieStore.get(url.host())的时候有值,代码运行到cookieStore.put(url.host(), cookies);的时候cookie值就丢失了,求教怎么处理?