PHPOffice / PhpSpreadsheet

        foreach ($this->getWorksheetIterator() as $sheet) {

            // from cells

            foreach ($sheet->getCellCollection(false) as $cellID) {

                $cell = $sheet->getCell($cellID);

                ++$countReferencesCellXf[$cell->getXfIndex()];

            }

            // from row dimensions

            foreach ($sheet->getRowDimensions() as $rowDimension) {

        // update the xfIndex for all cells, row dimensions, column dimensions

        foreach ($this->getWorksheetIterator() as $sheet) {

            // for all cells

            foreach ($sheet->getCellCollection(false) as $cellID) {

                $cell = $sheet->getCell($cellID);

                $cell->setXfIndex($map[$cell->getXfIndex()]);

            }

            // for all row dimensions

            foreach ($sheet->getRowDimensions() as $rowDimension) {