anchor.diff:           terminate/2, code_change/3]).
   
   -record(state, {
  +          tref = undefined :: timer:tref(),
             interval = 0 :: pos_integer(),
             active = [] :: list(tuple())
            }).
  
positive.code:     {stop, {unhandled_message, _Info}, State}.
  
  
  terminate(_Reason,_State) ->
      ok.
  
  
  
negative.code:     {reply, unknown_request, State}.
  
  handle_cast(inspect, #state{interval = Interval} = State) ->
      {ok, Active, TRef} = inspect_fun(Interval),
      {noreply, State#state{active = Active, tref = TRef}};
  
  handle_cast(_Msg, State) ->
      {noreply, State}.
  