addCol(rng, position) {
    const cell = dom.ancestor(rng.commonAncestor(), dom.isCell);
    const row = $(cell).closest('tr');
    const rowsGroup = $(row).siblings();
    rowsGroup.push(row);

    const vTable = new TableResultAction(cell, TableResultAction.where.Column,
      TableResultAction.requestAction.Add, $(row).closest('table')[0]);
    const actions = vTable.getActionList();

    for (let actionIndex = 0; actionIndex < actions.length; actionIndex++) {
      const currentCell = actions[actionIndex];
      const tdAttributes = this.recoverAttributes(currentCell.baseCell);
      switch (currentCell.action) {
        case TableResultAction.resultAction.AddCell:
          if (position === 'right') {
            $(currentCell.baseCell).after('<td' + tdAttributes + '>' + dom.blank + '</td>');
          } else {
            $(currentCell.baseCell).before('<td' + tdAttributes + '>' + dom.blank + '</td>');
          }
          break;
        case TableResultAction.resultAction.SumSpanCount:
          if (position === 'right') {
            let colspanNumber = parseInt(currentCell.baseCell.colSpan, 10);
            colspanNumber++;
            currentCell.baseCell.setAttribute('colSpan', colspanNumber);
          } else {
            $(currentCell.baseCell).before('<td' + tdAttributes + '>' + dom.blank + '</td>');
          }
          break;
      }
    }
  }
Add a new col

@param {WrappedRange} rng
@param {String} position (left/right)
@return {Node}