public static Builder builder() {
    return new Builder();
  }
@Test
  void whenReturnTypeIsResponseNoErrorHandling() {
    Map<String, Collection<String>> headers = new LinkedHashMap<>();
    headers.put("Location", Collections.singletonList("http://bar.com"));
    final Response response = Response.builder().status(302).reason("Found").headers(headers)
        .request(Request.create(HttpMethod.GET, "/", Collections.emptyMap(), null, Util.UTF_8))
        .body(new byte[0]).build();

    // fake client as Client.Default follows redirects.
    TestInterface api =
        Feign.builder().client((request, options) -> response).target(TestInterface.class,
            "http://localhost:" + server.getPort());

    assertThat(api.response().headers()).hasEntrySatisfying("Location", value -> {
      assertThat(value).contains("http://bar.com");
    });
  }