anchor.diff:              {reply, Result, {sequential, Pref, Seq + inc()}}
       end.
   
  +handle_cast(change, _State) ->
  +    {noreply, state()};
   handle_cast(stop, State) ->
       {stop, normal, State};
   handle_cast(_Msg, State) ->
  
positive.code: 
  inc() ->
      crypto:rand_uniform(1, 16#ffe).
  
negative.code:     list_to_binary(Prefix ++ couch_util:to_hex(crypto:rand_bytes(9))).
  
  init([]) ->
      ok = couch_config:register(
          fun("uuids", _) -> gen_server:cast(?MODULE, change) end
      ),
      {ok, state()}.
  
  terminate(_Reason, _State) ->
      ok.
  