anchor.diff:      case spawn_and_check(Fun, Num - 1) of
           ok ->
               receive
  -                ok ->
  -                    ct:print("bbb ~p", [Master]),
  -                    ok
  +                ok -> ok
               after ?REQUEST_TIMEOUT ->
  -                ct:print("ccc ~p", [Master]),
                   {error, timeout}
               end;
           E ->
  -            ct:print("ddd ~p ~p", [Master, E]),
               E
       end.
   
  
positive.code: 
  spawn_and_check(Fun, Num) ->
      Master = self(),
      ct:print("aaa ~p", [Master]),
      spawn_link(fun() ->
          Fun(),
          Master ! ok
  
negative.code:     ok;
  
  count_answers(Num, Exp) ->
      NumToBeReceived = Num + 1,
      Ans = receive
                #worker_answer{id = NumToBeReceived, response = Response} -> Response
            after ?REQUEST_TIMEOUT ->
                {error, timeout}
            end,
      ?assertEqual(pong, Ans),
      count_answers(NumToBeReceived, Exp).