@Override
    public Object getPrivateData() {
        return privateData;
    }

    @Override
    public <T> void setPrivateData(Class<? super T> type, T object) {
        setPrivateData(ModelType.of(type), object);
    }

    @Override
    public <T> void setPrivateData(ModelType<? super T> type, T object) {
        if (!isMutable()) {