public static function getSrcSetUrl(UriInterface $url, $size, $custom = null, $setWidthInUrl = true)
    {
        $identifier = substr($size, -1, 1);
        $size = substr($size, 0, -1);
        switch ($identifier) {
            case 'x':
                $uri = self::addOptionsToUri($url, 'options-dpr-'.$size);

                break;
            case 'w':
                if ($setWidthInUrl) {
                    $uri = self::addOptionsToUri($url, 'resize-width-'.$size);
                } else {
                    $uri = $url;
                }

                break;
            default:
                return $url;
        }
        if (null !== $custom) {
            $uri = self::getSrcSetUrlCustom($size, $custom, $setWidthInUrl, $uri);
        }

        return $uri;
    }