Must be used as base class for high level response provided by the controller that will be translated into something
at the portal level. The goal is to avoid to manipulate the HTTP response directly.
The test bed will of course use the HTTP response but the Presentation Framework will work differently.
So we really need to abstract everything done with the HttpServletResponse and *never* use it in the controller.
Typical usage should be : ControllerResponse response = controller.invoker(ControllerRequest request);