How to send a message to a whatsapp group with the venomous0x or yowsup api? [duplicate]

I would like to know, with an example if possible, how do I send a WhatsApp message to a group created by someone else using venomous0x or yowsup?

The shipping code is this:

public String sendMessage(String to, String message) throws WhatsAppException {
    return sendMessage(to, message, null);
}

/**
 * Send a text message to the user/group.
 *
 * @param String to The recipient.
 * @param String message The text message.
 * @param String id
 *
 * @return String
 */
public String sendMessage(String to, String message, String id) throws WhatsAppException {
    message = parseMessageForEmojis(message);
    ProtocolNode bodyNode = new ProtocolNode("body", null, null, message.getBytes());
    try {
        return sendMessageNode(to, bodyNode, id);
    } catch (Exception e) {
        throw new WhatsAppException("Failed to send message", e);
    }
}

/**
 * Send node to the servers.
 *
 * @param to The recipient to send.
 * @param node The node that contains the message.
 * @return message id
 * @throws IOException
 * @throws InvalidTokenException
 * @throws InvalidMessageException
 * @throws IncompleteMessageException
 * @throws WhatsAppException
 * @throws JSONException
 * @throws NoSuchAlgorithmException
 */
private String sendMessageNode(String to, ProtocolNode node, String id) throws IOException, IncompleteMessageException, InvalidMessageException, InvalidTokenException, WhatsAppException, JSONException, NoSuchAlgorithmException {
    ProtocolNode serverNode = new ProtocolNode("server", null, null, null);
    List<ProtocolNode> list = new LinkedList<ProtocolNode>();
    list.add(serverNode);
    Map<String, String> xHash = new LinkedHashMap<String, String>();
    xHash.put("xmlns", "jabber:x:event");
    ProtocolNode xNode = new ProtocolNode("x", xHash, list, null);
    Map<String, String> notify = new LinkedHashMap<String, String>();
    notify.put("xmlns", "urn:xmpp:whatsapp");
    notify.put("name", name);
    ProtocolNode notnode = new ProtocolNode("notify", notify, null, null);
    Map<String, String> request = new LinkedHashMap<String, String>();
    request.put("xmlns", "urn:xmpp:receipts");
    ProtocolNode reqnode = new ProtocolNode("request", request, null, null);

    Map<String, String> messageHash = new LinkedHashMap<String, String>();
    messageHash.put("to", getJID(to));
    messageHash.put("type", "chat");
    messageHash.put("id", (id == null ? createMsgId("message") : id));
    messageHash.put("t", time());

    list = new LinkedList<ProtocolNode>();
    list.add(xNode);
    list.add(notnode);
    list.add(reqnode);
    list.add(node);
    ProtocolNode messageNode = new ProtocolNode("message", messageHash, list, null);
    if (lastId == null) {
        lastId = messageHash.get("id");
        sendNode(messageNode);
        //listen for response
        waitForServer(messageHash.get("id"));
    } else {
        outQueue.add(messageNode);
    }
    eventManager().fireSendMessage(
            phoneNumber,
            getJID(to),
            messageHash.get("id"),
            node
    );
    return messageHash.get("id");
}

The test code is this:

public class TestSendMessageWhatsapp {

    public TestSendMessageWhatsapp() {
    }

    @BeforeClass
    public static void setUpClass() {
    }

    @AfterClass
    public static void tearDownClass() {
    }

    @Before
    public void setUp() {
    }

    @After
    public void tearDown() {
    }

    @Test
    public void hello() throws NoSuchAlgorithmException, WhatsAppException, IOException {

        String username = "5591XXXXXXXX", password = "/vuL76lOtEFfE5PE5Pw3Z3o6cXs=",
                identity = "mentorid", nickname = "mentor";

        boolean running = true;
        boolean loggedIn = false;
        WhatsApi wa = null;
        try {
            wa = new WhatsApi(username, identity, nickname);

            EventManager eventManager = new ExampleEventManager();
            wa.setEventManager(eventManager);
            MessageProcessor mp = new ExampleMessageProcessor();
            wa.setNewMessageBind(mp);

            if (!wa.connect()) {
                System.out.println("Failed to connect to WhatsApp");
                System.exit(1);
            }

            if (password != null) {
                wa.loginWithPassword(password);
                loggedIn = true;
            }
            ExampleMessagePoller poller = new ExampleMessagePoller(wa);
            poller.start();
            String msg = "send message by java...";

            //send message group  
            wa.sendMessage("5591XXXXXXXX-Mentor", msg);

            System.out.print("$ ");

            poller.setRunning(false);
            System.out.println("Done! Logging out");
            wa.disconnect();
        } catch (Exception e) {
            System.out.println("Caught exception: " + e.getMessage());
            e.printStackTrace();
            if (wa != null) {
                wa.disconnect();
            }
            System.exit(1);
        }
    }
}

And the result of the execution is this:

tx: <stream:features>
<receipt_acks></receipt_acks><status></status>
</stream:features>

tx: <auth xmlns="urn:ietf:params:xml:ns:xmpp-sasl" mechanism="WAUTH-1" user="559181196092"></auth>

tx: <response xmlns="urn:ietf:params:xml:ns:xmpp-sasl">a26d55bd313697d6de333cb89b3a91089d419d686e1cb98856032ca454b8386ac87f07174881a0e5c2c6f08dc25f</response>

tx: <presence type="available" name="mentor"></presence>

tx: <message to="[email protected]" type="chat" id="message-1420815830-1" t="1420815830">
<x xmlns="jabber:x:event">
<server></server>
</x><notify xmlns="urn:xmpp:whatsapp" name="mentor"></notify><request xmlns="urn:xmpp:receipts"></request><body>73656e64206d657373616765206279206a6176612e2e2e</body>
</message>

Event PRESENCE: phoneNumber=5591XXXXXXXX,[email protected],type=available

Event message_received_server: time=1420815892,phoneNumber=5591XXXXXXXX,msgId=message-1420815830-1,[email protected],type=chat

Event send_message: phoneNumber=5591XXXXXXXX

Thanks for the help right away.