'Make sure data is not saved when pickling a model.'

def test_pickle(self):

    model = Model(Domain([]))
    model.original_data = [1, 2, 3]
    model2 = pickle.loads(pickle.dumps(model))
    self.assertEqual(model.domain, model2.domain)
    self.assertEqual(model.original_data, [1, 2, 3])
    self.assertEqual(model2.original_data, None)
