anchor.diff:  code_change(_OldVsn, State, _Extra) -> {ok, State}.
   handle_cast(stop, State)            -> {stop, shutdown, State}.
   handle_info(_Info, State)           -> {noreply, State}.
  +
  +
  +handle_call({eval, Fun}, _From, State) ->
  +    {reply, catch Fun(State), State};
   
   handle_call(reload, _From, State) ->
       case init(State#config.init) of
  
positive.code: -export([stop/0, reload/0, resave/0, reannounce/0, replace/1]).
  
  %% API
  
  start_link(Full) ->
      gen_server:start_link({local, ?MODULE}, ?MODULE, Full, []).
  
negative.code: -define(RESAVE_FAILED, 2).
  -define(CONFIG_CONFLICT, 3).
  
  -export([eval/1,
           start_link/2, start_link/1,
           get_remote/1,
           merge/1,
           merge_remote/2, merge_remote/3,
  