class SimpleCatalogManager implements CatalogManager {

    @Override
    public Difference getDiff(Model original, Model changed) {
        Model originalCopy = mf.createModel(original);
        Model changedCopy = mf.createModel(changed);
        original.forEach(statement -> {
            Resource subject = statement.getSubject();
            IRI predicate = statement.getPredicate();
            Value object = statement.getObject();
            if (changedCopy.contains(subject, predicate, object)) {
                originalCopy.remove(subject, predicate, object);
                changedCopy.remove(subject, predicate, object);
            }
        });

        return new Difference.Builder()
                .additions(changedCopy)
                .deletions(originalCopy)
                .build();
    }

    public  SimpleCatalogManager();

}