anchor.diff:           remove/2,
            enabled/0,
            enable/0,
  +         subscribe/1,
            create_ensemble/4,
            create_ensemble/5,
            known_ensembles/0,
  
positive.code: -spec init([]) -> {ok, state()}.
  init([]) ->
      _ = ets:new(?ETS, [named_table, public, {read_concurrency, true}, {write_concurrency, true}]),
      State = reload_state(),
      schedule_tick(),
      true = ets:insert(?ETS, {cluster_state, State#state.cluster_state}),
      gen_server:cast(self(), init),
  
negative.code: -record(state, {version       :: integer(),
                  ensemble_data :: ensembles(),
                  remote_peers  :: orddict(peer_id(), pid()),
                  cluster_state :: cluster_state(),
                  subscribers :: [fun()]
                 }).
  
  -type state() :: #state{}.
  