protected function initializeCustomerAddress(array $attr)
    {

        // try to load the customer address with the given entity ID
        if ($entity = $this->loadCustomerAddress($attr[MemberNames::ENTITY_ID])) {
            return $this->mergeEntity($entity, $attr);
        }

        // remove the entity ID
        unset($attr[MemberNames::ENTITY_ID]);

        // simply return the attributes
        return $attr;
    }