anchor.diff:  %% @doc Receive a ping, makes sure that we stay alive
   ping(Pid) ->
       gen_server:cast(Pid, ping).
  +
  +session_pid(Pid) ->
  +    gen_server:call(Pid, session_pid).
   
   get_attach_state(Pid) ->
       try
  
positive.code:     stop/1, 
      ping/1,
      
      set/3, 
      get/2, 
      incr/3, 
  
negative.code: %%                                      {stop, Reason, State}
  %% @doc Handling call messages
  
  handle_call(session_pid, _From, State) ->
      {reply, State#page_state.session_pid, State};
  
  handle_call({spawn_link, Module, Func, Args}, _From, State) ->
      Pid    = spawn_link(Module, Func, Args),
      Linked = [Pid | State#page_state.linked],
  