class MySeriesHelper(SeriesHelper):
     class Meta:
        # ....

     @classmethod
     def commit(cls, client=None):
        # Overwrite this method to add the retention policy. This is a temp
        # hack until this can be applied to upstream.
        if not client:
            client = cls._client
        rtn = client.write_points(cls._json_body_(), retention_policy='my_retention_policy')
        cls._reset_()
        return rtn