Messaging send object

[edulid]

How to send an object to the client using the messaging module?
I tried to send a simple HashMap<String,Integer> but in the client-code instanceof is not working, so how to retrieve the original object ? (the client-side representation)

Using 6.0p power

[Isomorphic]

The client-side representation is going to be a JavaScript Object, with the Map's keys as property names, and the Map's values as property values.