@Override
    public Iterator<InternalFactHandle> iterateFactHandles() {
        return new CompositeFactHandleIterator(concreteStores, true);
    }
@Test
    public void iteratingOverFactHandlesHasSameNumberOfResultsAsIteratingOverObjects() throws Exception {
        insertObjectWithFactHandle(new SuperClass());
        insertObjectWithFactHandle(new SubClass());

        assertThat(collect(underTest.iterateFactHandles(SubClass.class))).hasSize(1);
        assertThat(collect(underTest.iterateFactHandles(SuperClass.class))).hasSize(2);
    }