@Post("/node/obj")
    @ProducesJson
    public Response json2(@RequestObject JsonNode input) {
        final JsonNode name = input.get("name");
        return new Response(Response.SUCCESS, name.textValue());
    }
Returns a {@link Response} object. The {@link ProducesJson} annotation makes an object be converted
as JSON string by the {@link JacksonResponseConverterFunction}.
examples/annotated-http-service/src/main/java/example/armeria/server/annotated/MessageConverterService.java