code: public void setCellMerge(final Table table, final int rowIndex,
  							 final int colIndex, final int rowMerge, final int columnMerge)
  			throws FastOdsException, IOException {
  		final TableCell cell = this.getCell(table, rowIndex, colIndex);
  		cell.setRowsSpanned(rowMerge);
  		cell.setColumnsSpanned(columnMerge);
  	}
docs: Set the merging of multiple cells to one cell.
  
  @param table       the table where the cells to merge are
  @param rowIndex    The row, 0 is the first row
  @param colIndex    The column, 0 is the first column
  @param rowMerge    the number of rows to merge
  @param columnMerge the number of columns to merge
  @throws FastOdsException if the rowIndex or the colIndex is negative
  @throws IOException if the cells can't be merged