getMerge = function(cellName) {
    const obj = this;

    let data = {};
    if (cellName) {
        if (obj.options.mergeCells && obj.options.mergeCells[cellName]) {
            data = [ obj.options.mergeCells[cellName][0], obj.options.mergeCells[cellName][1] ];
        } else {
            data = null;
        }
    } else {
        if (obj.options.mergeCells) {
            var mergedCells = obj.options.mergeCells;
            const keys = Object.keys(obj.options.mergeCells);
            for (let i = 0; i < keys.length; i++) {
                data[keys[i]] = [ obj.options.mergeCells[keys[i]][0], obj.options.mergeCells[keys[i]][1] ];
            }
        }
    }

    return data;
}
Merge cells
@param cellName
@param colspan
@param rowspan
@param ignoreHistoryAndEvents