reference a VIP's default pool within iRule?

when CLIENT_ACCEPTED {

    Save the name of the virtual server's default pool before it's change in this iRule
   set default_pool [LB::server pool]
}
when HTTP_REQUEST {
    switch -glob [HTTP::path] {
        "/abc/proxy.jsp" {
            pool $default_pool
        }
        "/xyz*" {
            pool  xyz_pool
        }
        ...
        default {
          pool $default_pool
        }
    }
}