anchor.diff:  
               %% Increment counter.
               {ok, _} = lasp:update(Counter, increment, Actor),
  +            {ok, _} = lasp:update(convergence_id(), {fst, increment}, Actor),
   
               %% Increment impressions.
               Impressions0 + 1
  
positive.code: %% Macros.
  -define(IMPRESSION_INTERVAL, 1000).
  -define(LOG_INTERVAL, 10000).
  
  %% State record.
  -record(state, {actor, impressions}).
  
negative.code:     erlang:send_after(?LOG_INTERVAL, self(), log).
  
  %% @private
  schedule_check_convergence() ->
      erlang:send_after(?CONVERGENCE_INTERVAL, self(), check_convergence).
  
  %% @private
  max_impressions() ->
      lasp_config:get(simulation_event_number, 10).
  
  %% @private
  client_number() ->
      ?NUM_NODES.
  
  %% @private
  convergence_id() ->
      PairType = {?PAIR_TYPE,
                      [
                          ?COUNTER_TYPE,
                          {?GMAP_TYPE, [?BOOLEAN_TYPE]}
                      ]
                  },
      {?CONVERGENCE_TRACKING, PairType}.
  