@Override
  public EpoxyModel<?> remove(int index) {
    notifyRemoval(index, 1);
    return super.remove(index);
  }
@Test
  public void testRemoveIndex() {
    EpoxyModel<?> removedModel = modelList.remove(0);
    assertFalse(modelList.contains(removedModel));

    assertEquals(2, modelList.size());
    verify(observer).onItemRangeRemoved(0, 1);
  }