def METHOD_NAME(marker, imputer):
    X = np.array(
        [
            [marker, 1, 5, marker, 1],
            [2, marker, 1, marker, 2],
            [6, 3, marker, marker, 3],
            [1, 2, 9, marker, 4],
        ]
    )
    X_true_indicator = np.array(
        [
            [1.0, 0.0, 0.0, 1.0],
            [0.0, 1.0, 0.0, 1.0],
            [0.0, 0.0, 1.0, 1.0],
            [0.0, 0.0, 0.0, 1.0],
        ]
    )
    imputer.set_params(missing_values=marker, add_indicator=True)
    X_trans = imputer.fit_transform(X)
    assert_allclose(X_trans[:, -4:], X_true_indicator)
    assert_array_equal(imputer.indicator_.features_, np.array([0, 1, 2, 3]))
    imputer.set_params(add_indicator=False)
    X_trans_no_indicator = imputer.fit_transform(X)
    assert_allclose(X_trans[:, :-4], X_trans_no_indicator)