code: private Cell findTemplateCell(ExcelRows excelRowsAnn) {
          val fromRef = excelRowsAnn.fromRef();
          if (PoiUtil.isFullCellReference(fromRef)) {
              val cellRef = new CellReference(fromRef);
              return sheet.getRow(cellRef.getRow()).getCell(cellRef.getCol());
          }
  
          val cellRef = new CellReference(fromRef + "1");
          val col = cellRef.getCol();
          val searchKey = excelRowsAnn.searchKey();
          for (int i = cellRef.getRow(), ii = sheet.getLastRowNum(); i <= ii; ++i) {
              val row = sheet.getRow(i);
              if (row == null) continue;
              val cell = row.getCell(col);
              if (cell == null) continue;
  
              val cellValue = PoiUtil.getCellStringValue(cell);
              if (StringUtils.contains(cellValue, searchKey)) return cell;
          }
  
          return null;
      }
docs: 查找模板单元格。
  
  @param excelRowsAnn ExcelRows注解
  @return 模板单元格。返回null，没有找到。