@Override
    public List<ValidationEvent> validate(Model model) {
        List<ValidationEvent> events = new ArrayList<>();
        model.shapes(ServiceShape.class).forEach(service -> validateService(model, service, events));
        return events;
    }
All {@code @auth} trait values referenced from an operation must refer
to authentication traits applied to service shapes that enclose the
operation.
smithy-model/src/main/java/software/amazon/smithy/model/validation/validators/AuthTraitValidator.java