15.4.5 简化元组的使用

public class Tuple{

    public static<A,B> TwoTuple<A,B> tuple(A a,B b){

   return new TwoTuple<A,B>(a,b);

}

}

public class TupleTest2{

  static TwoTuple<String,Integer> f(){

    return tuple("hi",47);

}

}