def test_a_non_layer_like_object_is_not_a_layer(self):
mock_not_a_layer = MockGroup("group not layer", None)
self.assertFalse(countersheet.is_layer(mock_not_a_layer))
def test_None_is_not_a_layer(self):
self.assertFalse(countersheet.is_layer(None))
def test_a_layer_like_object_is_a_layer(self):
mock_layer = MockGroup("layer", None)
self.assertTrue(countersheet.is_layer(mock_layer))
def test_number_is_not_a_layer(self):
self.assertFalse(countersheet.is_layer(4))