protected void addModel(EpoxyModel<?> modelToAdd) {
    int initialSize = models.size();

    pauseModelListNotifications();
    models.add(modelToAdd);
    resumeModelListNotifications();

    notifyItemRangeInserted(initialSize, 1);
  }
@Test
  public void testThrowIfChangeModelIdAfterNotify() {
    TestModel testModel = new TestModel();
    testModel.id(100);

    testAdapter.addModel(testModel);

    thrown.expect(IllegalEpoxyUsage.class);
    thrown.expectMessage("Cannot change a model's id after it has been added to the adapter");
    testModel.id(200);
  }