anchor.diff:      State3 = inc_r_msg_count(State2, length(Msg)),
       setelement(20, State3, NewList).
   
  --spec save_n_msgs([msg_or_tag()], fun((state(), [msg_or_tag()]) -> state()), state()) -> state().
  +-spec save_n_msgs([msg_or_tag()] | msg_or_tag(), fun((state(), [msg_or_tag()]) -> state()), state()) -> state().
   save_n_msgs(Msg, SaveFun, State) when is_tuple(Msg) ->
       save_n_msgs([{single, Msg}], SaveFun, State);
   save_n_msgs(Msgs, SaveFun, State) when is_list(Msgs) ->
  
positive.code: -spec get_msg_tag(msg_or_tag()) -> comm:msg_tag() | comm:message().
  get_msg_tag(Msg) ->
      {_Pid, ActualMessage} = Msg,
      ?IIF(?KEEP_MSG_OR_TAG =:= tag,
           util:extint2atom(comm:get_msg_tag(ActualMessage)),
           setelement(1, ActualMessage, util:extint2atom(element(1, ActualMessage)))).
  
  
negative.code:                              State2 = setelement(17, State1, 0),
                               inc_session_count(State2).
  
  -spec session_count(state()) -> non_neg_integer().
  session_count(State) -> element(18, State).
  -spec inc_session_count(state()) -> state().
  inc_session_count(State) -> setelement(18, State, session_count(State) + 1).
  