def test_update_and_get_image_is_called(self):
# holds all mock objects
mocker = Controller()
# mock object to be used in tested routine instead of real thing
mocked_game_state = mocker.mock()
# record exactly how mock object should be used in tested routine
mocked_game_state.update()
mocked_game_state.get_image((500, 500))
# prepare it for real use
mocker.replay()
# init states
manager = GameStateManager()
manager.state = "Mock"
manager._states["Mock"] = mocked_game_state
# call tested routine
screen = manager.get_rendered_screen((500, 500))
# test if it was used right
mocker.verify()
