@Override
    public List<ValidationEvent> validate(Model model) {
        List<ValidationEvent> events = new ArrayList<>();
        for (ServiceShape service : model.getServiceShapesWithTrait(ServiceTrait.class)) {
            validateService(service, service.expectTrait(ServiceTrait.class)).ifPresent(events::add);
        }
        return events;
    }
Service Id's that have already been shipped.

No new serviceId's should be added to this list in the future.
smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/SdkServiceIdValidator.java