Contribution by lnk. See issue #136.
jx:mergeCells( lastCell="Merge cell ranges" [, cols="Number of columns combined"] [, rows="Number of rows combined"] [, minCols="Minimum number of columns to merge"] [, minRows="Minimum number of rows to merge"] )
Note: This command can only be used on cells that have not been merged. An exception will occur if the scope of the merged cell exists for the merged cell.