docs: function addStateListeners() {
    this.state.on('connect', this.onConnect);
    this.state.on('disconnect', this.onDisconnect);
    this.state.on('rejected', this.onRejected);
    this.state.store.on('hit', this.onHit);
    this.state.store.on('miss', this.onMiss);
    this.state.store.on('expired', this.onExpired);
  }