anchor.diff:  handle_info(notify_clients, State) ->
       State2 = do_notify(State),
       {noreply, State2};
  +
  +handle_info(ping_all, State) ->
  +    ping_all(),
  +    {noreply, State};
   
   handle_info(_Msg, State) -> {noreply, State}.
   
  
positive.code: -module(ns_node_disco).
  
  -behaviour(gen_server).
  
  %% API
  -export([start_link/0,
  
negative.code: -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
           terminate/2, code_change/3]).
  
  -record(state, {nodes, timer}).
  
  -include_lib("eunit/include/eunit.hrl").
  
  