Map<String, Object> addProps = new HashMap<String, Object>();
addProps.put("foo", "bar");
addProps.put("foo2", "baz");
add.setAddProperties(addProps);
add.setMuleContext(muleContext);
add.initialise();
msg = (DefaultMuleMessage) add.transform(msg, (String)null);
assertEquals("bar", msg.getInvocationProperty("foo"));
assertNull(msg.getOutboundProperty("foo"));