InetAddress ipv6 = InetAddress.getByName("2001:db8::1");

        notification.addNewIPAddress(ipv4);
        notification.addNewIPAddress(ipv6);
        notification.addOldIPAddress(ipv4);

        List<WitnessNotification.WitnessIPAddress> newAddresses = notification.getNewIPAddresses();
        List<WitnessNotification.WitnessIPAddress> oldAddresses = notification.getOldIPAddresses();

        newIPAddresses.add(new WitnessIPAddress(address));
    }

    /**
     * Adds an old IP address to the notification.
     *
     * @param address the old IP address
     */
    public void addOldIPAddress(InetAddress address) {
        oldIPAddresses.add(new WitnessIPAddress(address));
    }

    // Getters and Setters

    /**
     * Gets the event type.
     *
     * @return the event type