private void internalNullTest(String prefix) throws Exception
{
MuleClient client = new MuleClient(muleContext);
Date message = new Date();
client.dispatch(prefix + "invoker.in", message, null);
MuleMessage reply = client.request(prefix + "invoker.out", RECEIVE_TIMEOUT);
assertNotNull(reply);
assertNull(reply.getExceptionPayload());
assertEquals(NullPayload.getInstance(), reply.getPayload());
}