anchor.diff:  handle_call({get_sink_loglevel, LoggerName, SinkName}, _From, State) ->
       RV = do_get_sink_loglevel(LoggerName, SinkName, State),
       handle_result(RV, State);
  +
  +handle_call(get_sink_names, _From, State) ->
  +    {reply, dict:fetch_keys(State#state.sinks), State};
   
   handle_call(_Request, _From, State) ->
       {reply, ok, State}.
  
positive.code:          set_loglevel/2, get_loglevel/1,
           set_sink_loglevel/3, get_sink_loglevel/2,
           sync_changes/1,
           sync_sink/1]).
  
  
  %% gen_server callbacks
  
negative.code:         exit:{noproc, _} ->
              {error, unknown_sink}
      end.
  
  sync_all_sinks() ->
      Sinks = gen_server:call(?MODULE, get_sink_names, infinity),
      [sync_sink(SinkName) || SinkName <- Sinks],
      ok.
  
  %% Callbacks
  init([MailboxLenLimit]) ->
  