def METHOD_NAME(tmp_path):
    with pytest.raises(ValueError) as info:
        clf = ak.StructuredDataClassifier(
            column_types={"age": "numerical", "parch": "categorical"},
            directory=tmp_path,
            seed=test_utils.SEED,
        )
        clf.fit(x=np.random.rand(100, 30), y=np.random.rand(100, 1))
    assert "column_names must be specified" in str(info.value)