def METHOD_NAME(data_1, data_2, expected):
    """Test the make_disjoint_train_set function."""
    test_df1 = pd.DataFrame([data_1])
    test_df2 = pd.DataFrame([data_2])
    disjoint = make_disjoint_train_set(test_df1, test_df2)
    assert disjoint.shape[0] == pytest.approx(
        expected, rel=pytest.rel_tolerance, abs=pytest.abs_tolerance
    )