anchor.diff:      {error, econnreset} = gen_tcp:recv(Server, PayloadSize),
       ok.
   
  +lz_make_payload(PayloadSize) ->
  +    list_to_binary(lists:duplicate(PayloadSize, $.)).
   
   %% THIS DOES NOT WORK FOR 'SOCKET'
   lz_ensure_non_empty_queue(Sock, Payload, OS) when is_port(Sock) ->
  
positive.code:     %% a connection when the driver queue is empty. We will test here
      %% that it also works when the driver queue is not empty
      %% and the linger zero option is set on the listen socket.
      {OS, _} = os:type(),
      ?P("create listen socket"),
      {ok, Listen} =
          ?LISTEN(Config, 0, [{active, false},
                             {recbuf, 4096},
                             {show_econnreset, true},
                             {linger, {true, 0}}]),
      {ok, Port} = inet:port(Listen),
      ?P("connect (create client socket)"),
      Client =
          case ?CONNECT(Config, localhost, Port,
                               [{active, false}, {sndbuf, 4096}]) of
              {ok, CSock} ->
                  CSock;
              {error, eaddrnotavail = Reason} ->
  
negative.code:        "~n   Socket info: ~p", [Sock, erlang:port_info(Sock)]),
      ct:fail("Queue size verification failed");
  lz_ensure_non_empty_queue(Sock, Payload, OS, N) ->
      ?P("try send payload (~w bytes) ~w (on client socket) when port info:"
         "~n   ~p", [byte_size(Payload), N, erlang:port_info(Sock)]),
      ok = gen_tcp:send(Sock, Payload),
      ?P("try verify client socket queue size"),
      case erlang:port_info(Sock, queue_size) of
  