/**
  * Prepare collection with passed data
  * @param mixed $data 
  */
 public function _prepare($filter = null)
 {
     $config = Mage::getConfig()->getNode($this->_scope[$filter])->children();
     foreach ($config as $node) {
         $path = $this->_scope[$filter] . '/' . $node->getName() . '/args';
         $conf = Mage::getConfig()->getNode($path)->children();
         foreach ($conf->modules as $modules) {
             $module = $modules->children();
             $item = new Varien_Object();
             $item->setTo((string) $module);
             $attributes = $module->attributes();
             $item->setFrom((string) $attributes[0]);
             $item->setDirection((string) $attributes->getName());
             $this->addItem($item);
         }
     }
 }