anchor.diff:      io:format("Unknown message received: ~p~n", [Msg]),
       {noreply, S}.
   
  +code_change(_OldVsn, State, _Extra) ->
  +    {ok, State}.
  +
   terminate(_Reason, _State) ->
       ok.
   
  
positive.code: -module(lmq_queue_server).
  -behaviour(gen_server).
  -compile(export_all).
  
  -include("lmq.hrl").
  -record(state, {refs=gb_sets:empty(), queue=queue:new()}).
  
  start() ->
      gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
  
  stop() ->
      gen_server:call(?MODULE, stop).
  
  push(Data) ->
      gen_server:call(?MODULE, {push, Data}).
  
negative.code:     end.
  
  test() ->
      lmq_queue_server:start_link(),
      ok = lmq_queue_server:push("foo"),
      M1 = lmq_queue_server:pull(),
      {_, UUID1} = M1#message.id,
  