anchor.diff:  -module(ns_node_disco).
   
   -behaviour(gen_server).
  --behavior(ns_log_categorizing).
   
   -include("ns_common.hrl").
   
  
positive.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").
  
  
negative.code:     global:sync(),
      % Register for nodeup/down messages as handle_info callbacks.
      ok = net_kernel:monitor_nodes(true),
      timer:send_interval(?PING_FREQ, ping_all),
      self() ! notify_clients,
      % Track the last list of actual ndoes.
      {ok, #state{nodes = []}}.
  
  terminate(_Reason, _State) ->
      ok.
  code_change(_OldVsn, State, _) -> {ok, State}.
  
  