Resource res = mock(Resource.class);
when(res.getChild("firstChild")).thenReturn(child);
when(res.getChild("secondChild")).thenReturn(secondChild);
when(res.getChild("emptyChild")).thenReturn(emptyChild);
ChildResourceModel model = factory.getAdapter(res, ChildResourceModel.class);
assertNotNull(model);
assertEquals(child, model.getFirstChild());
assertEquals(2, model.getGrandChildren().size());
assertEquals(firstGrandChild, model.getGrandChildren().get(0));
assertEquals(secondGrandChild, model.getGrandChildren().get(1));
assertEquals(0, model.getEmptyGrandChildren().size());
}