public function unmergeCellsByColumnAndRow($pColumn1 = 0, $pRow1 = 1, $pColumn2 = 0, $pRow2 = 1)
    {
        $cellRange = PHPExcel_Cell::stringFromColumnIndex($pColumn1) . $pRow1 . ':' . PHPExcel_Cell::stringFromColumnIndex($pColumn2) . $pRow2;
        return $this->unmergeCells($cellRange);
    }