anchor.diff:    ?check_trace(
        %% Run stage:
        begin
  +       O0 = SendFun(0),
  +       InitArgs = {true, [{0, O0}]},
          {ok, SubscriberPid} =
            brod:start_link_topic_subscriber(?CLIENT_ID, ?topic, ConsumerConfig,
                                             ?MODULE, InitArgs),
  -       SendFun(0),
          %% send some messages, ack some of them:
          [SendFun(I) || I <- lists:seq(1, 5)],
          {ok, #{offset := O3}} = wait_message(<<3>>),
  
positive.code:                    , {max_wait_time, 1000}
                     , {partition_restart_delay_seconds, 1}
                     ],
    InitArgs = {_IsAsyncAck = true, _CommittedOffsets = []},
    Partition = 0,
    SendFun =
      fun(I) ->
  
negative.code:      end,
       %% Check stage:
       fun(_Ret, Trace) ->
           Expected = [<<I>> || I <- lists:seq(1, 8)],
           check_received_messages(Expected, Trace),
           check_state_continuity(Trace),
           check_init_terminate(Trace)
  