For initial installations, see the [Setup topics](https://kubernetes.io/docs/setup/pick-right-solution/) in the Kubernetes documentation.

To upgrade to this release from a previous version, first take any actions required [Before Upgrading](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.9.md#before-upgrading).

    assertEquals(0, iterator.nextIndex());
    assertEquals(-1, iterator.previousIndex());
    assertThrows(NoSuchElementException.class, () -> iterator.next());
    assertThrows(NoSuchElementException.class, () -> iterator.previous());
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
    assertThrows(UnsupportedOperationException.class, () -> iterator.set("a"));

    assertEquals(0, iterator.nextIndex());
    assertEquals(-1, iterator.previousIndex());
    assertThrows(NoSuchElementException.class, () -> iterator.next());
    assertThrows(NoSuchElementException.class, () -> iterator.previous());
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
    assertThrows(UnsupportedOperationException.class, () -> iterator.set("a"));

    @Nullable Comparator<? super V> valueComparator;
    @Nullable Object[] alternatingKeysAndValues;
    int size;
    boolean entriesUsed;

    /**
     * If non-null, a duplicate key we found in a previous buildKeepingLast() or buildOrThrow()
     * call. A later buildOrThrow() can simply report this duplicate immediately.
     */
    @Nullable DuplicateKey duplicateKey;

    /**

## Urgent Upgrade Notes

### (No, really, you MUST do this before you upgrade)

  of obtaining data through LIST/WATCH semantics. ([#110772](https://github.com/kubernetes/kubernetes/pull/110772), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery]

  - [Important Security Information](#important-security-information-1)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-6)
    - [API Change](#api-change-1)
    - [Feature](#feature-4)
    - [Bug or Regression](#bug-or-regression-5)

* Fix device mountable volume names in DSW to prevent races in device mountable plugin, e.g. local. ([#71509](https://github.com/kubernetes/kubernetes/pull/71509), [@cofyc](https://github.com/cofyc))
* Fixes a bug in previous releases where a pod could be placed inside another pod's cgroup when specifying --cgroup-root ([#70678](https://github.com/kubernetes/kubernetes/pull/70678), [@dashpole](https://github.com/dashpole))

  - [Important Security Information](#important-security-information-1)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-9)
    - [API Change](#api-change-2)
    - [Feature](#feature-5)
    - [Bug or Regression](#bug-or-regression-9)

- Promoted JobSuccessPolicy E2E to...