@Test
  void queryMap_with_child_pojo_altered_by_getter_while_using_overriding_encoder()
      throws Exception {
    TestInterface api =
        new TestInterfaceBuilder()
            .queryMapEncoder(new FieldQueryMapEncoder())
            .target("http://localhost:" + server.getPort());

    ChildPojo childPojo = new ChildPojo();
    childPojo.setChildPrivateProperty("first");
    childPojo.setParentProtectedProperty("second");
    childPojo.setParentPublicProperty("third");
    childPojo.setParentPrivatePropertyAlteredByGetter("fourth");

    server.enqueue(new MockResponse());
    api.queryMapPropertyInheritenceWithBeanMapEncoder(childPojo);
    assertThat(server.takeRequest())
        .hasQueryParams(
            "parentPublicProperty=third",
            "parentProtectedProperty=second",
            "childPrivateProperty=first",
            "parentPrivatePropertyAlteredByGetter=fourthFromGetter");
  }
when you must parse a 2xx status to determine if the operation succeeded or not.
core/src/test/java/feign/FeignTest.java