testing, need to delete
Revert "fixed chart issues by using sheet index, turned Chart.add() into a @staticmethod, fixed naming of get_workbook_index into get_worksheet_index"

This reverts commit 42b3b60fcee68a1736f096e5ceaa2a99bea96d95.
Revert "Revert "fixed chart issues by using sheet index, turned Chart.add() into a @staticmethod, fixed naming of get_workbook_index into get_worksheet_index""

This reverts commit af6cf90061e18b0cdacaca9490446ee5ef94b524.
Revert "testing, need to delete"

This reverts commit 2fb262df4fe48e9562860ec0c58f73421510db9d.