@Test
  void timeoutTest() {
    server.enqueue(new MockResponse().setBody("foo").setHeadersDelay(1, TimeUnit.SECONDS));

    final TestInterface api =
        newBuilder()
            .retryer(Retryer.NEVER_RETRY)
            .options(
                new Request.Options(500, TimeUnit.MILLISECONDS, 500, TimeUnit.MILLISECONDS, true))
            .target(TestInterface.class, server.url("/").toString());

    FeignException exception = assertThrows(FeignException.class, () -> api.timeout());
    assertThat(exception).hasCauseInstanceOf(HttpTimeoutException.class);
  }
Tests client-specific behavior, such as ensuring Content-Length is sent when specified.
java11/src/test/java/feign/http2client/test/Http2ClientTest.java