[alibaba/easyexcel]excel模板导出，数据列表需要动态填充，动态填充的行数据需要合并单元格，测试发现动态填充7行没有问题，填充8行以上时就报错：Cannot add merged region C25:D25 to sheet because it overlaps with an existing merged region (B25:L25).

触发场景描述 按照excel模板导出xlsx文件，数据列表需要动态填充，动态填充的行数据需要合并单元格，测试发现动态填充7行没有问题，填充8行以上时就报错，如：Cannot add merged region C25:D25 to sheet because it overlaps with an existing merged region (B25:L25). 模板文件格式类似是这样的：

触发Bug的代码

            //单元格合并
            List<CellRangeAddress> cellRangeAddress = new ArrayList<>();
            if (CollectionUtil.isNotEmpty(excelVoList)) {
                if (excelVoList.size() > 1) {
                    for (int i = 0; i < excelVoList.size(); i++) {
                        cellRangeAddress.add(new CellRangeAddress(firstRow, lastRow, 2, 3));
                        cellRangeAddress.add(new CellRangeAddress(firstRow, lastRow, 7, 9));
                        cellRangeAddress.add(new CellRangeAddress(firstRow, lastRow, 12, 13));
                        firstRow++;
                        lastRow++;
                    }
                }
            }

           ......

         ExcelWriter excelWriter = EasyExcel.write(os).withTemplate(inputStream)
                    .registerWriteHandler(piFillMergeStrategy)
                    .build();
            WriteSheet writeSheet = EasyExcel.writerSheet().build();
            FillConfig fillConfig = FillConfig.builder().forceNewRow(Boolean.TRUE).build();

            //参数集合，直接写入到Excel数据
            excelWriter.fill(paramsMap, writeSheet);
            //列表数据
            excelWriter.fill(excelVoList, fillConfig, writeSheet);

单元格合并策略是这样的：

        @Override
        public void afterRowDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Integer relativeRowIndex, Boolean isHead) {
          if (CollectionUtil.isNotEmpty(cellRangeAddress)) {
            if (row.getRowNum() >= beginRow && row.getRowNum() <= beginRow + mergeRows) {
                for (CellRangeAddress item : cellRangeAddress) {
                    writeSheetHolder.getSheet().addMergedRegionUnsafe(item);
                }
            }
        }
    }

提示的异常或者没有达到的效果 同样的逻辑，数据列表7行（包括）以下导出没有问题，7行以上导出就会报错