anchor.diff:  %%--------------------------------------------------------------------
   handle_call(stop, _From, State) ->
       {stop, normal, ok, State};
  +handle_call(dirs, _From, State= #state {path_ref = Dirs}) ->
  +    io:format("Watched directories:\n ~p\n", [Dirs]),
  +    {reply, ok, State};
   handle_call(_Request, _From, State) ->
  +    io:format("Bad call: ~p\n", [_Request]),
       {reply, {error,bad_call}, State}.
   
   %%--------------------------------------------------------------------
  
positive.code: -export([start_link/0]).
  -export([start/0]).
  -export([stop/0]).
  
  %% gen_server callbacks
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  
negative.code: 
  stop() ->
      gen_server:call(?SERVER, stop).
  
  dirs() ->
      gen_server:call(?SERVER, dirs).
  
  %%%===================================================================
  %%% gen_server callbacks
  