@Override
    public HttpResponse serve(ServiceRequestContext ctx, HttpRequest req) {
        if (operation.isBlocking()) {
            return HttpResponse.of(req.aggregate().thenApplyAsync(invoke(ctx), ctx.blockingTaskExecutor()));
        } else {
            return HttpResponse.of(req.aggregate().thenApply(invoke(ctx)));
        }
    }
{@link HttpService} to handle a {@link WebOperation}. Mostly inspired by reactive implementation in
{@link AbstractWebFluxEndpointHandlerMapping}.
spring/boot3-actuator-autoconfigure/src/main/java/com/linecorp/armeria/spring/actuate/WebOperationService.java