setBillingAddress example

$addressIds = [];
        foreach ($customers as $customer) {
            $addressIds[] = $customer->getDefaultBillingAddressId();
            $addressIds[] = $customer->getDefaultShippingAddressId();
        }

        $addresses = $this->addressGateway->getList($addressIds);

        foreach ($customers as $id => &$customer) {
            $addressId = $customer->getDefaultBillingAddressId();
            if (\array_key_exists($addressId, $addresses)) {
                $customer->setBillingAddress($addresses[$addressId]);
            }

            $addressId = $customer->getDefaultShippingAddressId();
            if (\array_key_exists($addressId, $addresses)) {
                $customer->setShippingAddress($addresses[$addressId]);
            }
        }

        return $customers;
    }
}