I builded a class Couple:

```
public class Couple<E,K> {
    E first;    K second;

    Couple(E first, K second){
        this.first = first;
        this.second = second;
    }
    public E getFirst(){
        return first;
    }
    public K getSecond(){
        return second;
    }
}

```

And an `ArrayList<Couple<String, Integer>>`

```
ArrayList<Couple<URL, Integer>> a = ArrayList<Couple<URL, Integer>>();
a=fillArray();

```

I want to sort 'a' by the value of the second element of the couple that is an Integer.