Iterator<Tuple> it = input.iterator();
Tuple t1 = it.next();
Tuple t2 = it.next();
t1.append(2);
t2.append(3);
userFunc.attachInput(t1, t2);
Integer i = null;
// System.out.println(t1 + " " + t2);
int result = (Integer) (userFunc.getNextInteger().result);
assertEquals(-1, result);
}