gistfile1.php

<?php

// unit test: 
        foreach(array(Order::BILLING, Order::SHIPPING) as $type){
            ${$type."Address"}  = new CustomerAddress();

            ${$type."Address"}->setFirstName("{$type} First");
            ${$type."Address"}->setLastName("{$type} Last");
            ${$type."Address"}->setAddress1("{$type} 123 Main Street");
            ${$type."Address"}->setAddress2("{$type} Apt 123");
            ${$type."Address"}->setCity("{$type} New York");
            ${$type."Address"}->setState("{$type} NY");
            ${$type."Address"}->setPostalCode("{$type} 10011");
        }
        $order->setShippingAddress($shippingAddress);
        $order->setBillingAddress($billingAddress);

// Order.php 

    public function setShippingAddress(CustomerAddress $address)
    {
        $this->shippingName       = sprintf("%s %s", $address->getFirstName(), $address->getLastName());
        $this->shippingAddress1   = $address->getAddress1();
        $this->shippingAddress2   = $address->getAddress2();
        $this->shippingCity       = $address->getCity();
        $this->shippingState      = $address->getState();
        $this->shippingPostalCode = $address->getPostalCode();
    }

    public function setBillingAddress(CustomerAddress $address)
    {
        $this->billingName       = sprintf("%s %s", $address->getFirstName(), $address->getLastName());
        $this->billingAddress1   = $address->getAddress1();
        $this->billingAddress2   = $address->getAddress2();
        $this->billingCity       = $address->getCity();
        $this->billingState      = $address->getState();
        $this->billingPostalCode = $address->getPostalCode();
    }