def METHOD_NAME(
    df: Union[str, pd.Series, dd.Series, pd.DataFrame, dd.DataFrame],
    column: str = "",
) -> Union[bool, pd.Series, pd.DataFrame]:
    """
    Validate if a data cell is VAT in a DataFrame column. For each cell, return True or False.
    Parameters
    ----------
    df
            A pandas or Dask DataFrame containing the data to be validated.
    col
            The name of the column to be validated.
    """
    if isinstance(df, (pd.Series, dd.Series)):
        return df.apply(vat.is_valid)
    elif isinstance(df, (pd.DataFrame, dd.DataFrame)):
        if column != "":
            return df[column].apply(vat.is_valid)
        else:
            return df.applymap(vat.is_valid)
    return vat.is_valid(df)