public void swap(int first, int second) {
      if (second == -1) return;
      final Configuration one = myConfigurations.get(first);
      final Configuration two = myConfigurations.get(second);
      final int order = one.getOrder();
      one.setOrder(two.getOrder());
      two.setOrder(order);
      myConfigurations.set(second, one);
      myConfigurations.set(first, two);
    }
public void swap(int first, int second)