def METHOD_NAME():
    """Assert that the StackingEstimator returns transformed X based on test feature list 1."""
    ds = FeatureSetSelector(subset_list="tests/subset_test.csv", sel_subset="test_subset_1")
    ds.fit(test_X, y=None)
    transformed_X = ds.transform(test_X)
    assert transformed_X.shape[0] == test_X.shape[0]
    assert transformed_X.shape[1] != test_X.shape[1]
    assert transformed_X.shape[1] == 5
    assert np.array_equal(transformed_X, test_X[ds.feat_list].values)