@Override
    public HttpResponse serve(ServiceRequestContext ctx, HttpRequest req) throws Exception {
        final TranscodingSpec spec = routeAndSpecs.get(ctx.config().mappedRoute());
        if (spec != null) {
            return serve0(ctx, req, spec);
        }
        return unwrap().serve(ctx, req);
    }
Returns the {@link Route}s which are supported by this service and the {@code delegate}.
grpc/src/main/java/com/linecorp/armeria/server/grpc/HttpJsonTranscodingService.java