code: def add_worksheet(self):
          
          wsh = self.workbook.add_worksheet()
          if self.vars.fld2col_widths is not None:
              self.set_xlsx_colwidths(wsh, self.vars.fld2col_widths, self.wbfmtobj.get_prt_flds())
          return wsh
docs: Add a worksheet to the workbook.