anchor.diff:  		session_cache_client_max = 
   		    max_session_cache_size(session_cache_client_max),
   		session_cache_server_max = 
  -		    max_session_cache_size(session_cache_server_max)
  +		    max_session_cache_size(session_cache_server_max),
  +		session_client_invalidator = undefined,
  +		session_server_invalidator = undefined
   	       }}.
   
   %%--------------------------------------------------------------------
  
positive.code: handle_info(validate_sessions, #state{session_cache_cb = CacheCb,
  				      session_cache_client = ClientCache,
  				      session_cache_server = ServerCache,
  				      session_lifetime = LifeTime
  				     } = State) ->
      Timer = erlang:send_after(?SESSION_VALIDATION_INTERVAL, 
  			      self(), validate_sessions),
      start_session_validator(ClientCache, CacheCb, LifeTime),
      start_session_validator(ServerCache, CacheCb, LifeTime),
      {noreply, State#state{session_validation_timer = Timer}};
  
  
  handle_info({delayed_clean_session, Key, Cache}, #state{session_cache_cb = CacheCb
  
negative.code: %% Only start a session invalidator if there is not
  %% one already active
  invalidate_session_cache(undefined, CacheCb, Cache) ->
      start_session_validator(Cache, CacheCb, {invalidate_before, erlang:monotonic_time()}, undefined);
  invalidate_session_cache(Pid, _CacheCb, _Cache) ->
      Pid.
  