code: def wr_hdrs(self, worksheet, row_idx):
          
          for col_idx, hdr in enumerate(self.hdrs):
              # print("ROW({R}) COL({C}) HDR({H}) FMT({F})\n".format(
              #     R=row_idx, C=col_idx, H=hdr, F=self.fmt_hdr))
              worksheet.write(row_idx, col_idx, hdr, self.fmt_hdr)
          row_idx += 1
          return row_idx
docs: Print row of column headers