protected function _checkDeliveryStatus( $value )
	{
		$temp = (int) $value;

		if( $temp < MShop_Order_Item_Abstract::STAT_UNFINISHED || $temp > MShop_Order_Item_Abstract::STAT_RETURNED ) {
			throw new MShop_Order_Exception( sprintf( 'Order delivery status "%1$s" not within allowed range', $value ) );
		}
	}