How to use the pandarallel._pandarallel._DataFrameGroupBy function in pandarallel

def closure(df_grouped, func, *args, **kwargs):
            groups = list(df_grouped.groups.items())
            chunks = _chunk(len(groups), nb_workers)
            object_id = plasma_client.put(df_grouped.obj)
            groups_id = plasma_client.put(groups)

            with _ProcessPoolExecutor(max_workers=nb_workers) as executor:
                futures = [
                    executor.submit(_DataFrameGroupBy.worker,
                                    plasma_store_name, object_id,
                                    groups_id, chunk, func, *args, **kwargs)
                    for chunk in chunks
                ]

            result = _pd.DataFrame(list(itertools.chain.from_iterable([
                                    plasma_client.get(future.result())
                                    for future in futures
                                   ])),
                                   index=_pd.Series(list(df_grouped.grouper),
                                   name=df_grouped.keys)
                     ).squeeze()
            return result
        return closure