protected function formatSharedStringCellValue($nodeValue)
    {
        // shared strings are formatted this way:
        // <c r="A1" t="s"><v>[SHARED_STRING_INDEX]</v></c>
        $sharedStringIndex = intval($nodeValue);
        $escapedCellValue = $this->sharedStringsHelper->getStringAtIndex($sharedStringIndex);
        $cellValue = $this->escaper->unescape($escapedCellValue);
        return $cellValue;
    }