@Override
        public void onSubscribe(Subscription s) {
            subscription = s;
            s.request(Long.MAX_VALUE);
        }
Unlike {@link #contentPreviewBeforeEncoding()}, the content preview of this test is encoded data
because the previewing decorator is inserted after {@link EncodingService}.
core/src/test/java/com/linecorp/armeria/server/logging/ContentPreviewingServiceTest.java