anchor.diff:              timer:sleep(10),
   
               Pid = lists:nth(Random, ClientList),
  -            Pid ! view_ad
  +            Pid ! {runner, view_ad}
       end,
       lists:foreach(Viewer, lists:seq(1, NumEvents)),
       {ok, State}.
  
positive.code: %% @doc Wait for all events to be delivered in the system.
  wait(#state{count_events=Count, num_events=NumEvents}=State) ->
      receive
          view_ad ->
              case Count >= NumEvents of
                  true ->
                      {ok, State};
  
negative.code: %% @doc Client process; standard recurisve looping server.
  client(SetType, CounterType, SyncInterval, Runner, Id, AdsWithContractsId, AdsWithContracts0, Counters0) ->
      receive
          {runner, terminate} ->
              ok;
          {runner, view_ad} ->
              Counters = case dict:size(Counters0) of
                  0 ->
                      Counters0;
  