Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Axis.php
private function setGlowSize($size)
    {
        if ($size !== null) {
            $this->glowProperties['size'] = $this->getExcelPointsWidth($size);
        }

        return $this;
    }
private function setGlowSize($size)
    {
        if ($size !== null) {
            $this->glowProperties['size'] = $this->getExcelPointsWidth($size);
        }

        return $this;
    }
Set Glow Color.

@param float $size

@return Axis