code: function _updateMergeStartIndex(tableData, startRowIndex, endRowIndex) {
    tableData.slice(endRowIndex + 1).forEach(row => {
      row.forEach(cell => {
        if (util.isExisty(cell.rowMergeWith) && cell.rowMergeWith >= startRowIndex) {
          cell.rowMergeWith = endRowIndex + 1;
        }
      });
    });
  }
docs: Update row merge start index to merged cell.
  @param {Array.<Array.<object>>} tableData - table data
  @param {number} startRowIndex - start row index
  @param {number} endRowIndex - end row index
  @private