Mapper::isExternal PHP Method

    public static function isExternal($path)
    {
        return preg_match('/^[\\w]+:/', $path);
    }

 public function asset($url, $name, $extension = null)
 {
     if (!Mapper::isExternal($url)) {
         if (!is_null($extension)) {
             $url = $this->extension($url, $extension);
         }
         $url = Mapper::url($url, false, self::$assets[$name]);
     }
     return $url;
 }