`Interrupted(error) bool` helper to replace checks for `err == ErrWaitTimeout`, or compare specifically to context errors as needed. A future release will make the `ErrWaitTimeout` error private and callers must use `Interrupted()` instead. If you are returning `ErrWaitTimeout` from your own methods, switch to creating a location specific `cause err` and pass it to the new method `wait.ErrorInterrupted(cause) error` which will ensure `Interrupted()` returns true for your loop. 
  
  The `wa...

- Fixed recursive LIST from watch cache returning object matching key. ([#125584](https://github.com/kubernetes/kubernetes/pull/125584), [@serathius](https://github.com/serathius)) [SIG API Machinery and Testing]

- The Usage and VolumeCondition are both optional in the response and if CSIVolumeHealth feature gate is enabled kubelet needs to consider returning metrics if either one is set. ([#127021](https://github.com/kubernetes/kubernetes/pull/127021), [@Madhu-1](https://github.com/Madhu-1)) [SIG Storage]

- Added alpha support for `WindowsHostNetworking` feature. ([#112961](https://github.com/kubernetes/kubernetes/pull/112961), [@marosset](https://github.com/marosset))
- Added alpha support for returning container and pod metrics from CRI, instead of cAdvsior. ([#113609](https://github.com/kubernetes/kubernetes/pull/113609), [@haircommander](https://github.com/haircommander))

- Added validation to ensure `log-flush-frequency` is a positive value, returning an error instead of causing a panic. ([#133540](https://github.com/kubernetes/kubernetes/pull/133540), [@BenTheElder](https://github.com/BenTheElder)) [SIG Architecture, Instrumentation, Network and Node]

        "multiset.entrySet.retainAll(presentEntry) returned false",
        getMultiset().entrySet().retainAll(singleton(Multisets.immutableEntry(e0(), 1))));
    assertTrue(
        "multiset doesn't contains element after retaining its entry",
        getMultiset().contains(e0()));
  }

  @CollectionSize.Require(ONE)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testEntrySet_retainAllAbsent() {
    assertTrue(

        "multiset.entrySet.retainAll(presentEntry) returned false",
        getMultiset().entrySet().retainAll(singleton(Multisets.immutableEntry(e0(), 1))));
    assertTrue(
        "multiset doesn't contains element after retaining its entry",
        getMultiset().contains(e0()));
  }

  @CollectionSize.Require(ONE)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testEntrySet_retainAllAbsent() {
    assertTrue(

  
  **How can I migrate?**
  
  For backward compatibility, nil `QueueingHintFn` is treated as always returning QueueAfterBackoff. 
  So, if you want to just keep the existing behavior, you can register `ClusterEventWithHint` with no `QueueingHintFn` in it. 

- Kube-apiserver: fixes scale subresource patch handling to avoid returning unnecessary 409 Conflict error to clients ([#90342](https://github.com/kubernetes/kubernetes/pull/90342), [@liggitt](https://github.com/liggitt)) [SIG Apps, Autoscaling and Testing]

* Protobuf serialization does not distinguish between `[]` and `null`.
API fields previously capable of storing and returning either `[]` and `null` via JSON API requests (for example, the Endpoints `subsets` field)
can now store only `null` when created using the protobuf content-type or stored in etcd using protobuf serialization (the default in 1.6).