* iterate over keys in their enum definition order, not encounter order.
   *
   * <p>If the mapped keys contain duplicates, the values are merged using the specified merging
   * function.
   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K extends Enum<K>, V>
      Collector<T, ?, ImmutableMap<K, V>> toImmutableEnumMap(

Node.  There is an open PR ([#48189](https://github.com/kubernetes/kubernetes/pull/48189)) to resolve this issue, but as this issue also exists in 1.6, and as we do not wish to risk release stability by merging it directly prior to a release without sufficient testing, we have decided to defer merging the PR until the next point release for each minor version ([#48190](https://github.com/kubernetes/kubernetes/pull/48190)).

* Protobuf serialization does not distinguish between `[]` and `null`....

          <name>id</name>
          <type>String</type>
          <required>true</required>
          <description>The unique id for this report set, to be used during POM inheritance and profile injection
            for merging of report sets.
          </description>
          <defaultValue>default</defaultValue>
        </field>
        <field>
          <name>reports</name>
          <version>4.0.0+</version>

    /**
     * Number of days to keep search logs before purging.
     * Set to -1 to disable automatic purging of search logs.
     */
    @Min(-1)
    @Max(100000)
    @ValidateTypeFailure
    public Integer purgeSearchLogDay;

    /**
     * Number of days to keep job logs before purging.
     * Set to -1 to disable automatic purging of job logs.
     */
    @Min(-1)
    @Max(100000)

- Kubeadm: add the deprecated flag --port=0 to kube-controller-manager and kube-scheduler manifests to disable insecure serving. Without this flag the components by default serve (e.g. /metrics) insecurely on the default node interface (controlled by --address). Users that wish to override this behavior and enable insecure serving can pass a custom --port=X via kubeadm's "extraArgs" mechanic for these components. ([#92720](https://github.com/kubernetes/kubernetes/pull/92720),...

    /**
     * Default constructor for PurgeDocJob.
     * Creates a new instance of the document purging job with default settings.
     */
    public PurgeDocJob() {
        // Default constructor
    }

    /**
     * Executes the document purging job.
     * Removes all documents from the search index that have expired based on their expires field.
     *

built using golang 1.17. This version of go removes the ability to use a `GODEBUG=x509ignoreCN=0` environment setting to re-enable deprecated legacy behavior of treating the CommonName of X.509 serving certificates as a host name. This behavior has been disabled by default since Kubernetes 1.19 / go 1.15. Serving certificates used by admission webhooks, custom resource conversion webhooks, and aggregated API servers must now include valid Subject Alternative Names. If you are running Kubernetes 1.22...

     * Creates a new instance of the thumbnail purging job with default expiry time (30 days).
     */
    public PurgeThumbnailJob() {
        // Default constructor
    }

    /** Expiration time for thumbnails in milliseconds (default: 30 days) */
    private long expiry = 30 * 24 * 60 * 60 * 1000L;

    /**
     * Executes the thumbnail purging job.

* Warn user when using `apply` on a resource lacking the `LastAppliedConfig` annotation ([#36672](https://github.com/kubernetes/kubernetes/pull/36672), [@ymqytw](https://github.com/ymqytw))
* PATCH (i.e. apply and edit) now supports merging lists of primitives ([#38665](https://github.com/kubernetes/kubernetes/pull/38665), [@ymqytw](https://github.com/ymqytw))

    /**
     * Default constructor for PurgeLogJob.
     * Creates a new instance of the log purging job with default settings.
     */
    public PurgeLogJob() {
        // Default constructor
    }

    /**
     * Executes the log purging job.
     * Performs the following cleanup operations:
     * - Purges old crawling sessions
     * - Purges search logs older than configured days