XmppSession xmppSession1 = new TestXmppSession(ROMEO, mockServer);
XmppSession xmppSession2 = new TestXmppSession(JULIET, mockServer);
RpcManager rpcManager = xmppSession1.getExtensionManager(RpcManager.class);
rpcManager.executorService = new SameThreadExecutorService();
rpcManager.setEnabled(true);
rpcManager.setRpcHandler(new RpcHandler() {
@Override
public Value process(Jid requester, String methodName, List<Value> parameters) throws RpcException {
if (methodName.equals("square")) {