def METHOD_NAME(df: pd.DataFrame, members: List[str], region: str, remove_members: bool = True) -> pd.DataFrame:
    """Aggregate data for a region.
    This function is useful when adding regions that are not currently considered by etl.data_helpers.geo.add_region_aggregates.
    For instance "Europe Union (28)". Or when a region is built differently, e.g. Europe = EU 28 + ...
    """
    # Mask
    msk_region = df["country"].isin(members)
    df_region = df[msk_region].copy()
    df_region["country"] = region
    df_region = df_region.groupby(["country", "year", "chemical"], as_index=False)[["consumption"]].sum()
    if remove_members:
        df = pd.concat([df[~msk_region], df_region], ignore_index=True)
    else:
        df = pd.concat([df, df_region], ignore_index=True)
    return df