code: def _open_worksheet(self, xlsx_file):
          
          workbook = Workbook(xlsx_file, {'in_memory': True})
          worksheet = workbook.add_worksheet()
          yield workbook, worksheet
          workbook.close()
docs: Enable XlsxWriter Worksheet object to be opened, operated on, and
          then automatically closed within a `with` statement. A filename or
          stream object (such as a ``BytesIO`` instance) is expected as
          *xlsx_file*.