code: public static Cell getOrCreateCell(Row row, int cellIndex) {
  		Cell cell = row.getCell(cellIndex);
  		if (null == cell) {
  			cell = row.createCell(cellIndex);
  		}
  		return cell;
  	}
docs: 获取已有行或创建新行
  
  @param row Excel表的行
  @param cellIndex 列号
  @return {@link Row}
  @since 4.0.2