docs: function _updateColspan(tableData, startColIndex, endColIndex) {
    tableData.forEach(rowData => {
      util.range(startColIndex, endColIndex + 1).forEach(colIndex => {
        const cellData = rowData [colIndex];
  
        if (util.isExisty(cellData.colMergeWith)) {
          const merger = rowData [cellData.colMergeWith];
  
          if (merger.colspan) {
            merger.colspan -= 1;
          }
        } else if (cellData.colspan > 1) {
          const lastMergedCellIndex = colIndex + cellData.colspan - 1;
  
          cellData.colspan -= (endColIndex - colIndex + 1);
  
          if (lastMergedCellIndex > endColIndex) {
            rowData [endColIndex + 1] = util.extend({}, cellData);
          }
        }
      });
    });
  }