class Tuple3 extends Tuple2<T1, T2> implements Tuple {

    @Override
    public String toString() {
        return "Tuple{" +
                "item1=" + item1 +
                ",item2=" + item2 +
                ",item3=" + item3 +
                '}';
    }

      Tuple3(T1 a, T2 b, T3 c);

}