I'm using the Grails REST client builder plugin (<https://github.com/grails-plugins/grails-rest-client-builder>) like so:

```
final def rest = new RestBuilder(connectTimeout:connectTimeout, readTimeout:readTimeout)
final def resp = rest.get(uri) 

```

So the server always returns the result as XML - how do I (the client) specify that I want the result as JSON?