private static List<DiffStrategy> createStrategiesForShape(Shape shape, boolean allowContents) {
        List<DiffStrategy> strategies = new ArrayList<>();

        for (String tag : shape.getTags()) {
            DiffStrategy value = DiffStrategy.fromTag(tag, allowContents);
            if (value != null) {
                strategies.add(value);
            }
        }

        return strategies;
    }
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