anchor.diff:  -spec schedule_flush(state()) -> state().
   schedule_flush(State) ->
       Delay = application:get_env(cluster_worker, datastore_writer_flush_delay,
  -        timer:seconds(1)),
  +        ?DEFAULT_FLUSH_DELAY),
       schedule_flush(State, Delay).
   
   %%--------------------------------------------------------------------
  
positive.code: -type request() :: term().
  -type state() :: #state{}.
  -type cached_token_map() ::
  #{reference() =>{datastore_links_iter:token(), erlang:timestamp()}}.
  
  -define(REV_LENGTH,
      application:get_env(cluster_worker, datastore_links_rev_length, 16)).
  
  %%%===================================================================
  %%% API
  
negative.code:         {undefined, _} ->
              Timer = erlang:send_after(Delay, self(), flush),
              State#state{flush_timer = Timer};
          {_, ?FAST_FLUSH_DELAY} ->
              case application:get_env(?CLUSTER_WORKER_APP_NAME, tp_fast_flush, on) of
                  on ->
                      erlang:cancel_timer(OldTimer, [{async, true}, {info, false}]),
  