Craft\MinimeeService::isUrl PHP Method

    protected function isUrl($string)
    {
        // from old _isURL() file from Carabiner Asset Management Library
        // modified to support leading with double slashes
        return preg_match('@((https?:)?//([-\\w\\.]+)+(:\\d+)?(/([\\w/_\\.]*(\\?\\S+)?)?)?)@', $string) > 0;
    }