def test_count(self):
data = ModelDataSet(Apple)
self.assertEqual(data.count(), 0)
apple = Apple(name="test")
apple.save()
self.assertEqual(data.count(), 1)
filtered = data.filter(name="test")
self.assertEqual(filtered.count(), 1)
empty = data.filter(name="invalid")
self.assertEqual(empty.count(), 0)
