@Test
    void givenHttpClientUriPathAndRequestPath_whenGet_thenRequestToConcatenatedPath() throws Exception {
        final BlockingWebClient client = BlockingWebClient.of(server.httpUri() + "/hello");

        final AggregatedHttpResponse response = client.get("/world");

        assertThat(response.contentUtf8()).isEqualTo("success");
    }
User-agent header should be overridden by ClientOption.HTTP_HEADER
core/src/test/java/com/linecorp/armeria/client/HttpClientIntegrationTest.java