protected function _extractQuoteShippingData(Mage_Sales_Model_Quote $quote)
    {
        $shippingData = array();
        foreach ($quote->getAllShippingAddresses() as $address) {
            $shippingData[] = array(
                'method' => $address->getShippingMethod(),
                'address' => $this->_extractAddressData($address),
            );
        }
        return $shippingData;
    }