===== 获取回调函数中的值 =====
<code>
    AtomicReference<String> body = new AtomicReference<>();
    client.call(
        request,
        response -> {
          try {
            body.set(new String(response.body().readAllBytes(), Charset.defaultCharset()));
          } catch (IOException ex) {
            throw new RuntimeException(ex);
          }
        },
        new RequestOptions()
            .setUrl("https://yaocheng.cn/cat/add")
            .setTimeout(Duration.of(1L, ChronoUnit.SECONDS)));

</code>