def METHOD_NAME():
    sample_df = pd.DataFrame(
        {
            "COUNTRY": ["France", "USA"] * 4,
            "PRODUCT": (["PRODUCT A"] * 2 + ["PRODUCT B"] * 2) * 2,
            "YEAR": ["2019"] * 4 + ["2020"] * 4,
            "VALUE": [5, 10, 10, 15, 20, 20, 30, 25],
        }
    )
    step = TotalsStep(
        name="totals",
        totalDimensions=[TotalDimension(total_column="COUNTRY", total_rows_label="All countries")],
        aggregations=[Aggregation(columns=["VALUE"], aggfunction="sum", newcolumns=["VALUE"])],
        groups=[],
    )
    expected_result = pd.concat(
        [
            sample_df,
            pd.DataFrame(
                {"COUNTRY": "All countries", "PRODUCT": [None], "YEAR": [None], "VALUE": [135]}
            ),
        ]
    )
    real_result = execute_totals(step, sample_df)
    assert_dataframes_equals(real_result, expected_result)