anchor.diff:  
   %% API
   -export([add_handler/0]).
  -%% Perhaps useful to the outside world.
  --export([format_pretty_proc_info/1, format_pretty_proc_info/2,
  -         get_pretty_proc_info/1, get_pretty_proc_info/2]).
   
   %% gen_event callbacks
   -export([init/1, handle_event/2, handle_call/2,
  
positive.code:     try
          case get_pretty_proc_info(Pid, Acf) of
              undefined ->
                  "";
              Res ->
                  io_lib:format("~w", [Res])
          end
      catch X:Y ->
              io_lib:format("Pid ~w, ~W ~W at ~w\n",
                            [Pid, X, 20, Y, 20, erlang:get_stacktrace()])
      end.
  
  get_pretty_proc_info(Pid) ->
  
negative.code: handle_event({monitor, Pid, Type, Info}, State=#state{timer_ref=TimerRef}) ->
      %% Reset the inactivity timeout
      NewTimerRef = reset_timer(TimerRef),
      {Fmt, Args} = format_pretty_proc_info(Pid, almost_current_function),
      lager:info("monitor ~w ~w "++ Fmt ++ " ~w",
                            [Type, Pid] ++ Args ++ [Info]),
      {ok, State#state{timer_ref=NewTimerRef}};
  handle_event(Event, State=#state{timer_ref=TimerRef}) ->
      NewTimerRef = reset_timer(TimerRef),
  