anchor.diff:      lists:subtract(nodes_actual_proper(), [node()]).
   
   nodes_wanted() ->
  -    gen_server:call(?MODULE, nodes_wanted).
  +    do_nodes_wanted().
   
   % API's used as callbacks that are invoked when ns_config
   % keys have changed.
  
positive.code: handle_call(nodes_actual_proper, _From, State) ->
      {reply, do_nodes_actual_proper(), State};
  
  handle_call(nodes_wanted, _From, State) ->
      {reply, do_nodes_wanted(), State};
  
  handle_call(Msg, _From, State) ->
      ?log_warning("Unhandled ~p call: ~p", [?MODULE, Msg]),
      {reply, error, State}.
  
negative.code: % Read from ns_config nodes_wanted.
  
  do_nodes_wanted() ->
      case ns_config:search(nodes_wanted) of
          {value, L} -> lists:usort(L);
          false      -> []
      end.
  