docs: public Mono<ServiceMessage> requestOne(ServiceMessage request, Class<?> responseType) {
      return Mono.defer(
          () -> {
            String qualifier = request.qualifier();
            if (methodRegistry.containsInvoker(qualifier)) { // local service.
              return methodRegistry
                  .getInvoker(request.qualifier())
                  .invokeOne(request, ServiceMessageCodec::decodeData)
                  .map(this::throwIfError);
            } else {
              return addressLookup(request)
                  .flatMap(address -> requestOne(request, responseType, address)); // remote service
            }
          });
    }