@Test
public void shouldFilterByIsNotNull() {

	DummyModel model = createModel("column1", "column2");
	DummyModel model1 = createModel("column1", null);
	Filter filter = new Filter(new Condition("column1", Operator.is_not_null));
	List<DummyModel> models = DummyModel.where(filter);
	assertEquals(models.size(), 2);
	assertEquals(models.get(0), model);
	assertEquals(models.get(1), model1);
}