Summary

        Returns:
            TYPE: Description

def sum(self):
        """Summary

        Returns:
            TYPE: Description
        """
        return GroupedDataFrameWeld(
            grizzly_impl.groupby_sum(
                self.columns,
                self.column_types,
                self.grouping_columns,
                self.grouping_column_types
            ),
            self.grouping_column_names,
            self.column_names,
            self.grouping_column_types,
            self.column_types
        )