public void refreshCouples (ArrayList <Piston> others){
        if (others.size() > 1){
            couples.clear();
            for (int i = 0; i < others.size(); i ++){
                for (int j = i+1; j < others.size(); j++){
                    if (i != j) {
                        couples.add(new Couple(others.get(i), others.get(j)));
                    }
                }
            }
        }
    }