public function setService( MShop_Order_Item_Base_Service_Interface $service, $type )
	{
		$this->_checkPrice( $service->getPrice() );

		$this->_notifyListeners( 'setService.before', $service );

		// enforce that the type is the same as the given one
		$service->setType( $type );

		$this->_services[$type] = clone $service;
		$this->_modified = true;

		$this->_notifyListeners( 'setService.after', $service );

		return $this->_services[$type];
	}