private static void checkGetRequest(String path, BlockingWebClient client) throws Exception {
        final AggregatedHttpResponse response = client.get(path);
        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