def test_factory_subclasses():
    factory = EventSourceFactory()
    assert len(factory.subclass_names) > 0
def test_factory_incorrect_use():
    with pytest.raises(FileNotFoundError):
        dataset = get_dataset_path("gamma_test_large.simtel.gz")
        factory = EventSourceFactory(input_url=dataset)
        reader = factory.produce()
        assert reader is not None