code: public static Row getOrCreateRow(Sheet sheet, int rowIndex) {
  		Row row = sheet.getRow(rowIndex);
  		if (null == row) {
  			row = sheet.createRow(rowIndex);
  		}
  		return row;
  	}
docs: 获取已有行或创建新行
  
  @param sheet Excel表
  @param rowIndex 行号
  @return {@link Row}
  @since 4.0.2