anchor.diff:  
   spawn_and_check(Fun, Num) ->
       Master = self(),
  -    ct:print("aaa ~p", [Master]),
       spawn_link(fun() ->
           Fun(),
           Master ! ok
  
positive.code:     case spawn_and_check(Fun, Num - 1) of
          ok ->
              receive
                  ok ->
                      ct:print("bbb ~p", [Master]),
                      ok
              after ?REQUEST_TIMEOUT ->
                  ct:print("ccc ~p", [Master]),
                  {error, timeout}
              end;
          E ->
              ct:print("ddd ~p ~p", [Master, E]),
              E
      end.
  
  
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).