gistfile1.php

  class ResourceList extends ArrayObject{
    private static $resolver = '';
    private $resolved = false;

    public static function set_resolver($method){
      self::$resolver = explode('::', $method);
    }
    public function load(){
      if($this->resolved !== false) return $this->resolved;
      $this->resolved = array();
      $method = self::$resolver;
      foreach($this as $url){
        $this->resolved[] = call_user_func($method, $url);
      }
      return $this->resolved;
    }
  }