@Test
  void beanQueryMapEncoderWithPrivateGetterIgnored() throws Exception {
    TestInterfaceAsync api =
        new TestInterfaceAsyncBuilder()
            .queryMapEndcoder(new BeanQueryMapEncoder())
            .target("http://localhost:" + server.getPort());

    PropertyPojo.ChildPojoClass propertyPojo = new PropertyPojo.ChildPojoClass();
    propertyPojo.setPrivateGetterProperty("privateGetterProperty");
    propertyPojo.setName("Name");
    propertyPojo.setNumber(1);

    server.enqueue(new MockResponse());
    CompletableFuture<?> cf = api.queryMapPropertyPojo(propertyPojo);
    assertThat(server.takeRequest()).hasQueryParams(Arrays.asList("name=Name", "number=1"));
    checkCFCompletedSoon(cf);
  }
when you must parse a 2xx status to determine if the operation succeeded or not.
core/src/test/java/feign/AsyncFeignTest.java