public static function mergeStatic($new = null, array $old = [])
    {
        // Parses the string into an associative array
        parse_str(preg_replace('/\s*([\w-]+)\s*=\s*"([^"]+)"/', '$1=$2&', $new), $attrs);

        // Merge classes
        $attrs['class'] = self::formatGroupClass($attrs, $old);

        // Merging new and old array and parse it as a string
        return self::attributes(array_merge(Arr::except($old, array('class')), $attrs));
    }