anchor.diff:  -define(ARTIFACT_MESSAGE,  artifact).
   
   %% State record.
  --record(state, {attempted_nodes, graph}).
  +-record(state, {is_connected, was_connected, attempted_nodes, graph}).
   
   %%%===================================================================
   %%% API
  
positive.code:             %% All nodes should attempt to refresh the membership.
              timer:send_after(?REFRESH_INTERVAL, ?REFRESH_MESSAGE)
      end,
      {ok, #state{attempted_nodes=sets:new(), graph=digraph:new()}}.
  
  %% @private
  -spec handle_call(term(), {pid(), term()}, #state{}) ->
  
negative.code:     end,
  
      timer:send_after(?BUILD_GRAPH_INTERVAL, ?BUILD_GRAPH_MESSAGE),
      {noreply, State#state{is_connected=IsConnected,
                            was_connected=WasConnected,
                            graph=Graph}};
  
  handle_info(Msg, State) ->
      _ = lager:warning("Unhandled messages: ~p", [Msg]),
      {noreply, State}.
  