clientOptions.setUseSeparateListener(true);
serviceClient.setOptions(clientOptions);
TestCallback callback1 = new TestCallback ("Callback 1");
serviceClient.sendReceiveNonBlocking(getEchoOMBlock("echo1",sequenceKey),callback1);
clientOptions.setProperty(SandeshaClientConstants.LAST_MESSAGE, "true");
TestCallback callback2 = new TestCallback ("Callback 2");
serviceClient.sendReceiveNonBlocking (getEchoOMBlock("echo2",sequenceKey),callback2);