[Seaside] url rewrite (http 304) with seaside / pharo 3

[nova]

Hi,

I an new to seaside and playing with it. When a session is started I
want to make a url check and if it fits some conditions to do an url
rewrite (http 304).

I think I found the place where to make this check: initialRequest:
But I can't find how to send a url rewrite back (I don't want to use an
external http-server for that rewrite).

Any help will be appreciated :)

P.