@Override
            List<ValidationEvent> validate(
                    Model model,
                    String path,
                    Shape shape,
                    ShapeId trait,
                    Node left,
                    Node right,
                    Severity severity
            ) {
                List<ValidationEvent> events = new ArrayList<>();
                events.addAll(ADD.validate(model, path, shape, trait, left, right, severity));
                events.addAll(REMOVE.validate(model, path, shape, trait, left, right, severity));
                events.addAll(UPDATE.validate(model, path, shape, trait, left, right, severity));
                return events;
            }
Traits in this list have special backward compatibility rules and can't be validated here.
smithy-diff/src/main/java/software/amazon/smithy/diff/evaluators/ModifiedTrait.java