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

        final AggregatedHttpResponse response =
                client.execute(RequestHeaders.of(HttpMethod.GET, "/encoding-toosmall"));
        assertThat(response.headers().get(HttpHeaderNames.CONTENT_ENCODING)).isNull();
        assertThat(response.contentUtf8()).isEqualTo("small content");
    }
User-agent header should be overridden by ClientOption.HTTP_HEADER
core/src/test/java/com/linecorp/armeria/client/HttpClientIntegrationTest.java