@Test
    void produceIsCalledWhenRequestCanceled() throws Exception {
        final HttpRequestWriter request = HttpRequest.streaming(RequestHeaders.of(HttpMethod.GET, "/"));
        request.write(HttpData.ofUtf8("foo"));
        final ContentPreviewer contentPreviewer = contentPreviewer();

        final ServiceRequestContext ctx = ServiceRequestContext.of(request);
        final HttpRequest filteredRequest = ContentPreviewingUtil.setUpRequestContentPreviewer(
                ctx, request, contentPreviewer, Functions.second());
        filteredRequest.subscribe(new CancelSubscriber());

        assertThat(ctx.log()
                      .whenAvailable(RequestLogProperty.REQUEST_CONTENT_PREVIEW)
                      .join()
                      .requestContentPreview()).isEqualTo("foo");
    }
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