anchor.diff:       end,
        %% Check stage:
        fun(_Ret, Trace) ->
  -         Expected = [<<I>> || I <- lists:seq(0, 8)],
  +         Expected = [<<I>> || I <- lists:seq(1, 8)],
            check_received_messages(Expected, Trace),
            check_state_continuity(Trace),
            check_init_terminate(Trace)
  
positive.code: 
  %% Check that for any `init' there is a `terminate':
  check_init_terminate(Trace) ->
    ?strict_causality( #{worker_id := _ID, ?snk_kind := topic_subscriber_init}
                     , #{worker_id := _ID, ?snk_kind := topic_subscriber_terminate}
                     , Trace
                     ).
  
  
negative.code:                    , {sleep_timeout, 0}
                     , {max_wait_time, 1000}
                     ],
    ?check_trace(
       %% Run stage:
       begin
         O0 = produce({?topic, 0}, <<0>>),
         InitArgs = {true, [{0, O0}]},
         {ok, SubscriberPid} =
           brod:start_link_topic_subscriber(?CLIENT_ID, ?topic, ConsumerConfig,
                                            ?MODULE, InitArgs),
         %% Send messages:
         Messages = [<<I>> || I <- lists:seq(1, MaxSeqNo)],
         [produce({?topic, 0}, I) || I <- Messages],
         %% Ack messages:
         wait_and_ack(SubscriberPid, Messages),
         ok = brod_topic_subscriber:stop(SubscriberPid),
         Messages
       end,
       %% Check stage:
       fun(Expected, Trace) ->
  