private static String getValidationEventId(DiffType diffType, ShapeId trait) {
            return String.format("%s.%s.%s",
                    ModifiedTrait.class.getSimpleName(),
                    StringUtils.capitalize(StringUtils.lowerCase(diffType.toString())),
                    trait);
        }
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