public function Cleanup() {
      foreach ($this->_Objects as $FactoryInstanceName => &$FactoryInstance) {
         if (!is_array($FactoryInstance)) continue;
         $FactoryType = $FactoryInstance['FactoryType'];
         
         if (!array_key_exists($FactoryType, $FactoryInstance)) continue;
         $FactoryObject = &$FactoryInstance[$FactoryType];
         
         if (method_exists($FactoryObject, 'Cleanup'))
            $FactoryObject->Cleanup();
         
         unset($FactoryInstance);
      }
   }