Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Html.php
private function writeComment(Worksheet $pSheet, $coordinate)
    {
        $result = '';
        if (!$this->isPdf && isset($pSheet->getComments()[$coordinate])) {
            $result .= '<a class="comment-indicator"></a>';
            $result .= '<div class="comment">' . nl2br($pSheet->getComment($coordinate)->getText()->getPlainText()) . '</div>';
            $result .= PHP_EOL;
        }

        return $result;
    }
private function writeComment(Worksheet $pSheet, $coordinate)
    {
        $result = '';
        if (!$this->isPdf && isset($pSheet->getComments()[$coordinate])) {
            $result .= '<a class="comment-indicator"></a>';
            $result .= '<div class="comment">' . nl2br($pSheet->getComment($coordinate)->getText()->getPlainText()) . '</div>';
            $result .= PHP_EOL;
        }

        return $result;
    }
Write a comment in the same format as LibreOffice.

@see https://github.com/LibreOffice/core/blob/9fc9bf3240f8c62ad7859947ab8a033ac1fe93fa/sc/source/filter/html/htmlexp.cxx#L1073-L1092

@param Worksheet $pSheet
@param string $coordinate

@return string