// iteration support for a recursive tree data structure
type Tree[K cmp.Ordered, V any] struct {
	left, right *Tree[K, V]
	key         K
	value       V
}

func (t *Tree[K, V]) walk(yield func(key K, val V) bool) bool {
	return t == nil || t.left.walk(yield) && yield(t.key, t.value) && t.right.walk(yield)
}

func (t *Tree[K, V]) Walk(yield func(key K, val V) bool) {
	t.walk(yield)

- github.com/cncf/udpa/go: [5459f2c](https://github.com/cncf/udpa/go/tree/5459f2c)
- github.com/cockroachdb/errors: [v1.2.4](https://github.com/cockroachdb/errors/tree/v1.2.4)
- github.com/cockroachdb/logtags: [eb05cc2](https://github.com/cockroachdb/logtags/tree/eb05cc2)
- github.com/coredns/caddy: [v1.1.0](https://github.com/coredns/caddy/tree/v1.1.0)

  // value automatically if one of them is empty and the other is non-empty.
  // When namespace is specified in dataSourceRef,
  // dataSource isn't set to the same value and must be empty.
  // There are three important differences between dataSource and dataSourceRef:
  // * While dataSource only allows two specific types of objects, dataSourceRef
  //   allows any non-core object, as well as PersistentVolumeClaim objects.

### SIG AWS

In v1.13 we worked on tighter integrations of Kubernetes API objects with AWS services. These include three out-of-tree alpha feature releases:

1) Alpha for AWS ALB (Application Load Balancer) integration to Kubernetes Ingress resources.
2) Alpha for CSI specification 0.3 integration to AWS EBS (Elastic Block Store)

  - Do not use the `PersistentVolumeLabel` admission controller in the configuration files and scripts unless you are dependent on the in-tree GCE and AWS cloud providers.

  - The `PersistentVolumeLabel` admission controller will be removed in a future release, when the out-of-tree versions of the GCE and AWS cloud providers move to GA. The cloud providers are marked alpha in version 1.9.

### OpenStack

  * Added support for printing in all supported `--output` formats to `kubectl create ...` and `kubectl apply ...` ([#38112](https://github.com/kubernetes/kubernetes/pull/38112), [@juanvallejo](https://github.com/juanvallejo))
  * Add three more columns to `kubectl get deploy -o wide` output. ([#39240](https://github.com/kubernetes/kubernetes/pull/39240), [@xingzhou](https://github.com/xingzhou))

- github.com/antlr/antlr4/runtime/Go/antlr/v4: [8188dc5](https://github.com/antlr/antlr4/runtime/Go/antlr/v4/tree/8188dc5)
- github.com/google/gnostic-models: [v0.6.8](https://github.com/google/gnostic-models/tree/v0.6.8)
- github.com/googleapis/enterprise-certificate-proxy: [v0.2.3](https://github.com/googleapis/enterprise-certificate-proxy/tree/v0.2.3)

([#64706](https://github.com/kubernetes/kubernetes/pull/64706), [@liztio](https://github.com/liztio))

* Action required: validation rule on metadata.initializers.pending[x].name is tightened. The initializer name needs to contain at least three segments separated by dots. If you create objects with pending initializers, (i.e., not relying on apiserver adding pending initializers according to initializerconfiguration), you need to update the initializer name in existing objects and in configuration...

hub.com/kubernetes/enhancements/issues/547). Kubernetes v1.10 also ships with the beta release of the [CRI validation test suite](https://github.com/kubernetes/enhancements/issues/292).

The Resource Management Working Group graduated three features to beta in the 1.10 release.  First, [CPU Manager](https://kubernetes.io/docs/tasks/administer-cluster/cpu-management-policies/), which allows users to request exclusive CPU cores.  This helps performance in a variety of use-cases, including...