def check_classes_shape(name):
    # Test that n_classes_ and classes_ have proper shape.
    ForestClassifier = FOREST_CLASSIFIERS[name]

    # Classification, single output
    clf = ForestClassifier(random_state=0).fit(X, y)

    assert_equal(clf.n_classes_, 2)
    assert_array_equal(clf.classes_, [-1, 1])

    # Classification, multi-output
    _y = np.vstack((y, np.array(y) - 2)).T
    clf = ForestClassifier(random_state=0).fit(X, _y)

    assert_array_equal(clf.n_classes_, [2, 2])
    assert_array_equal(clf.classes_, [[-1, 1], [-2, 2]])
dataset/ETHPy150Open scikit-learn/scikit-learn/sklearn/ensemble/tests/test_forest.py/check_classes_shape/operator `*` -> `-`