private HttpResponse serve0(ServiceRequestContext ctx, HttpRequest req) {
        final AggregationType aggregationType =
                AnnotatedValueResolver.aggregationType(aggregationStrategy, req.headers());

        if (aggregationType == AggregationType.NONE && !useBlockingTaskExecutor) {
            // Fast-path: No aggregation required and blocking task executor is not used.
            switch (responseType) {
                case HTTP_RESPONSE:
                    final HttpResponse res = (HttpResponse) invoke(ctx, req, AggregatedResult.EMPTY);
                    assert res != null;
                    return res;
                case OTHER_OBJECTS:
                    return convertResponse(ctx, invoke(ctx, req, AggregatedResult.EMPTY));
            }
        }

        deferRequestContent(ctx, req);

        return HttpResponse.of(serve1(ctx, req, aggregationType));
    }
An {@link HttpService} which is defined by a {@link Path} or HTTP method annotations.
This class is not supposed to be instantiated by a user. Please check out the documentation
<a href="https://armeria.dev/docs/server-annotated-service">Annotated HTTP Service</a> to use this.
core/src/main/java/com/linecorp/armeria/internal/server/annotation/DefaultAnnotatedService.java