@Test
    void httpDecoding() throws Exception {
        final BlockingWebClient client = WebClient.builder(server.httpUri())
                                                  .factory(clientFactory)
                                                  .decorator(DecodingClient.newDecorator())
                                                  .build()
                                                  .blocking();

        try (ClientRequestContextCaptor captor = Clients.newContextCaptor()) {
            final AggregatedHttpResponse response =
                    client.execute(RequestHeaders.of(HttpMethod.GET, "/encoding"));
            final RequestLog log = captor.get().log().whenComplete().join();
            assertThat(log.responseHeaders().get(HttpHeaderNames.CONTENT_ENCODING))
                    .isEqualTo(Brotli.isAvailable() ? "br" : "gzip");
            assertThat(response.contentUtf8()).isEqualTo(
                    "some content to compress more content to compress");
        }
    }
User-agent header should be overridden by ClientOption.HTTP_HEADER
core/src/test/java/com/linecorp/armeria/client/HttpClientIntegrationTest.java