MuleMessage msg = new DefaultMuleMessage("testing", muleContext);
msg.setReplyTo("ReplyTo");
// Send asynchronous request
client.dispatch("EchoAxisSend", msg, null);
// Wait for asynchronous response
MuleMessage result = client.request("ReplyTo", RECEIVE_DELAY);
assertNotNull("Result is null", result);
assertFalse("Result is null", result.getPayload() instanceof NullPayload);