@Test
public void testSingleInput() throws Exception {

    Stitch func = new Stitch();
    Tuple t = TupleFactory.getInstance().newTuple();
    t.append(new Integer(1));
    DataBag b = BagFactory.getInstance().newDefaultBag();
    b.add(t);
    t = TupleFactory.getInstance().newTuple();
    t.append(b);
    DataBag out = func.exec(t);
    assertEquals(1, out.size());
    assertEquals(new Integer(1), out.iterator().next().get(0));
}