class Tuple4 extends Tuple3<T1, T2, T3> implements Tuple {

    @Override
    public String toString() {
        return "Tuple{" +
                "item1=" + item1 +
                ",item2=" + item2 +
                ",item3=" + item3 +
                ",item4=" + item4 +
                '}';
    }

      Tuple4(T1 a, T2 b, T3 c, T4 d);

}