@Streaming(false)
        @Get("/httpDataMono")
        public Mono<HttpData> httpDataMono() {
            return Mono.just(HttpData.ofUtf8("httpDataMono"));
        }
A mock service for testing {@link ByteArrayResponseConverterFunction}.
core/src/test/java/com/linecorp/armeria/internal/server/annotation/ResponseStreamingTest.java