anchor.diff:      ?line {_, D} = ttb:stop([fetch, return_fetch_dir]),
       ?line ttb:format(D, [{out, ?OUTPUT}, {handler, simple_call_handler()}]),
       ?line {ok, Ret} = file:consult(?OUTPUT),
  -    ?line true = (2*(NumMsgs + 1) == length(Ret)).
  +    check_output(2*(NumMsgs + 1),Ret).
   changing_cwd_on_remote_node(cleanup,_Config) ->
       ?line stop_client_and_server().
   
  
positive.code:     ?line {_, D} = ttb:stop([fetch, return_fetch_dir]),
      ?line ttb:format(D, [{out, ?OUTPUT}, {handler, simple_call_handler()}]),
      ?line {ok, Ret} = file:consult(?OUTPUT),
      ?line true = (2*(NumMsgs + 1) == length(Ret)),
      ?line ok = file:set_cwd(OldDir).
  changing_cwd_on_control_node(cleanup,_Config) ->
      ?line stop_client_and_server().
  
  
negative.code: 
  simple_call_handler() ->
      {fun(A, {trace_ts, _, call, _, _} ,_,_) -> io:format(A, "ok.~n", []);
  	(A, {drop, N}, _, _) -> io:format(A, "{drop, ~p}.", [N]);
  	(_, end_of_trace, _, _) -> ok end, []}.
  
  marking_call_handler() ->
  