public function each($collection=null, $iterator=null) {
    list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);
    
    if(is_null($collection)) return self::_wrap(null);
    
    $collection = (array) self::_collection($collection);
    if(count($collection) === 0) return self::_wrap(null);
    
    foreach($collection as $k=>$v) {
      call_user_func($iterator, $v, $k, $collection);
    }
    return self::_wrap(null);
  }