anchor.diff:              {stop, gone}
       end.
   
  -handle_call(list_queues, _From, State = #state{sharded_queues = Qs}) ->
  -    {reply, gb_sets:to_list(Qs), State};
  -
   handle_call(Msg, _From, State) ->
       {stop, {unexpected_call, Msg}, State}.
   
  
positive.code: all() ->
      pg2_fixed:create(rabbit_topic_shards),
      pg2_fixed:get_members(rabbit_topic_shards).
  
  x(XName) ->
      pg2_fixed:create({rabbit_topic_shard, XName}),
      pg2_fixed:get_members({rabbit_topic_shard, XName}).
  
  %%----------------------------------------------------------------------------
  
  
negative.code: %% before 'go' gets invoked. Ignore.
  handle_cast(go, State) ->
      {noreply, State};
  
  handle_cast(_Msg, State = {not_started, _}) ->
      {noreply, State};
  