ensure that idempotency is preserved.

[github-actions]

https://api.github.com/psykei/psyki-python/blob/d1f30c225397da708932d38146c98de769a9c4ca/test/psyki/fuzzifiers/test_lukasiewicz.py#L66

    )
    functions = fuzzifier.visit(knowledge)

    def disabled_test_on_dataset(self):
        # TODO: ensure that idempotency is preserved.
        dataset = SpliceJunction.get_train()
        x, y = dataset.iloc[:, :-1], dataset.iloc[:, -1:]
        y = np.eye(3)[y.astype(int)].reshape([y.shape[0], 3])