@Override
            public void onNext(HttpObject obj) {
                // No data frames.
                assertThat(obj).isInstanceOf(HttpHeaders.class);
                assertThat(obj.isEndOfStream()).isTrue();
            }
Test for issues that may happen when doing simple proxying.
it/server/src/test/java/com/linecorp/armeria/server/http/HttpProxyIntegrationTest.java