class BooleanDifference implements IDifference {

    @Override
    public String toString() {
        return name + ":" + (first == null ? "NA" : (first ? "T" : "F")) + "/"
               + (second == null ? "NA" : (second ? "T" : "F"));
    }

    private  BooleanDifference(String name, Boolean first, Boolean second);

}