@Override
    public void onRemoval(RemovalNotification<Object, Object> notification) {}
  }

  enum OneWeigher implements Weigher<Object, Object> {
    INSTANCE;

    @Override
    public int weigh(Object key, Object value) {
      return 1;
    }
  }

  static final Ticker NULL_TICKER =
      new Ticker() {
        @Override
        public long read() {
          return 0;
        }

* 'kubectl describe pv' now shows events ([#27431](https://github.com/kubernetes/kubernetes/pull/27431), [@jsafrane](https://github.com/jsafrane))
* AWS kube-up: set net.ipv4.neigh.default.gc_thresh1=0 to avoid ARP over-caching ([#27682](https://github.com/kubernetes/kubernetes/pull/27682), [@justinsb](https://github.com/justinsb))