private function writePageMargins(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
    {
        // pageMargins
        $objWriter->startElement('pageMargins');
        $objWriter->writeAttribute('left', StringHelper::formatNumber($pSheet->getPageMargins()->getLeft()));
        $objWriter->writeAttribute('right', StringHelper::formatNumber($pSheet->getPageMargins()->getRight()));
        $objWriter->writeAttribute('top', StringHelper::formatNumber($pSheet->getPageMargins()->getTop()));
        $objWriter->writeAttribute('bottom', StringHelper::formatNumber($pSheet->getPageMargins()->getBottom()));
        $objWriter->writeAttribute('header', StringHelper::formatNumber($pSheet->getPageMargins()->getHeader()));
        $objWriter->writeAttribute('footer', StringHelper::formatNumber($pSheet->getPageMargins()->getFooter()));
        $objWriter->endElement();
    }