public function validateCompletedOrderAddress(Varien_Event_Observer $observer)
    {
        /** @var Fontis_Australia_Helper_Address $helper */
        $helper = Mage::helper('australia/address');
        if (!$helper->isValidationOrderSaveEnabled()) {
            return;
        }

        try {
            /** @var Mage_Sales_Model_Order $order */
            $order = $observer->getOrder();
            if (!$order || !$order->getShippingAddress()) {
                return;
            }

            $helper->validateOrderAddress($order);
            $order->save();
        } catch (Exception $err) {
            Mage::logException($err);
        }
    }