public function getImageSize($aImgSizes, $sIndex = null)
    {
        $aSize = [];
        if (isset($sIndex) && is_array($aImgSizes) && isset($aImgSizes[$sIndex])) {
            $aSize = explode('*', $aImgSizes[$sIndex]);
        } elseif (is_string($aImgSizes)) {
            $aSize = explode('*', $aImgSizes);
        }
        if (is_array($aSize) && 2 == count($aSize)) {
            $x = (int) $aSize[0];
            $y = (int) $aSize[1];
            if ($x && $y) {
                return $aSize;
            }
        }

        return null;
    }