anchor.diff:  %%%===================================================================
   %%% Internal functions
   %%%===================================================================
  -get_message_passing_counters(Node, Proplist, Vizceral) ->
  +get_message_passing_counters(Node, Proplist, Vizceral, OldMsgPass) ->
       lists:foldl(
         fun({send, Send}, V) ->
                 %% Examples of send trace:
                 %% {{global_name_server,<13104.13.0>},0,1}
                 %% {#Port<13104.431>,<13104.28.0>},0,72}
                 %% {{<13104.12.0>,{alias,'erlangpl@127.0.0.1'}},2,0}
  -              update_message_passing_graph(Node, Send, V);
  +              update_message_passing_graph(Node, Send, V, OldMsgPass);
            (_, V) ->
                 V
         end,
         Vizceral,
         Proplist).
   
  -update_message_passing_graph(Node, Send, Vizceral) ->
  +update_message_passing_graph(Node, Send, Vizceral, OldMsgPass) ->
       %% Below is a workaround for how Vizceral requires the INTERNET
       %% node to appear in its graph
       {{RootVertex, _}, _, _} = hd(Send),
       Viz1 = push_focused(<<"INTERNET">>, Node, Vizceral),
       Viz2 = push_focused(RootVertex, Node, Viz1),
       Viz3 = push_focused_connection(
  -                  <<"INTERNET">>, RootVertex, Node, {0,0,0}, #{}, Viz2),
  +             <<"INTERNET">>, RootVertex, Node, {0,0,0}, Viz2),
   
       %% Update Vizceral graph with verticies representing processes
       %% and edges representing message passing
  
positive.code:          code_change/3]).
  
  -record(state, {subscribers = [],
                  counters = []}).
  
  %%%===================================================================
  %%% API functions
  
negative.code:     ok = epl:subscribe(),
  
      %% Initialise counters, so that later we can calculate deltas
      TrafficCounters = get_traffic_counters(),
      {ok, #state{traffic = TrafficCounters}}.
  
  handle_call(Request, _From, _State) ->
      exit({not_implemented, Request}).
  