@Post("/obj/future")
    @ProducesJson
    public CompletionStage<Response> json4(@RequestObject Request request,
                                           ServiceRequestContext ctx) {
        final CompletableFuture<Response> future = new CompletableFuture<>();
        ctx.blockingTaskExecutor()
           .submit(() -> future.complete(new Response(Response.SUCCESS, request.name())));
        return future;
    }
Returns a {@link CompletionStage} object. The {@link JacksonResponseConverterFunction} will
be executed after the future is completed with the {@link Response} object.

<p>Note that the {@link ServiceRequestContext} of the request is also automatically injected. See
<a href="https://armeria.dev/docs/server-annotated-service#other-classes-automatically-injected">
Other classes automatically injected</a> for more information.
examples/annotated-http-service/src/main/java/example/armeria/server/annotated/MessageConverterService.java