@Test (dataProvider = "getIterable")
public void testExpand(Iterable iterable, int size)  {

  final TridentTuple tuple = mock(TridentTuple.class);
  final TridentCollector collector = mock(TridentCollector.class);
  when(tuple.getValue(0)).thenReturn(iterable);
  Expand expand = new Expand();
  expand.execute(tuple, collector);
  verify(tuple, times(1)).getValue(0);
  verify(collector, times(size)).emit(any(Values.class));
}