* specific length.
   *
   * <p>For example, if you need 1024-bit hash codes, you could join two {@link Hashing#sha512} hash
   * functions together: {@code Hashing.concatenating(Hashing.sha512(), Hashing.sha512())}.
   *
   * @since 19.0
   */
  public static HashFunction concatenating(
      HashFunction first, HashFunction second, HashFunction... rest) {

/**
 * Static methods for implementing hash-based collections.
 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Austin Appleby
 */
@GwtCompatible
final class Hashing {
  private Hashing() {}

  /*
   * These should be ints, but we need to use longs to force GWT to do the multiplications with
   * enough precision.
   */
  private static final long C1 = 0xcc9e2d51;

/**
 * Static methods for implementing hash-based collections.
 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Austin Appleby
 */
@GwtCompatible
final class Hashing {
  private Hashing() {}

  /*
   * These should be ints, but we need to use longs to force GWT to do the multiplications with
   * enough precision.
   */
  private static final long C1 = 0xcc9e2d51;

#### kube-apiserver:
- in an `--encryption-provider-config` config file, an explicit `cacheSize: 0` parameter previously silently defaulted to caching 1000 keys. In Kubernetes 1.18, this now returns a config validation error. To disable caching, you can specify a negative cacheSize value in Kubernetes 1.18+.

- Kube-apiserver: Added support for disabling caching of authorization webhook decisions in the `--authorization-config` file. The new fields `cacheAuthorizedRequests` and `cacheUnauthorizedRequests` could be set to `false` to prevent caching for authorized or unauthorized requests. See the https://kubernetes.io/docs/reference/access-authn-authz/authorization/#using-configuration-file-for-authorization...

* AWS: Remove duplicate calls to DescribeInstance during volume operations ([#39842](https://github.com/kubernetes/kubernetes/pull/39842), [@gnufied](https://github.com/gnufied))
* Caching added to the OIDC client auth plugin to fix races and reduce the time kubectl commands using this plugin take by several seconds. ([#38167](https://github.com/kubernetes/kubernetes/pull/38167), [@ericchiang](https://github.com/ericchiang))

- Avoid caching the Azure VMSS instances whose network profile is nil ([#100948](https://github.com/kubernetes/kubernetes/pull/100948), [@feiskyer](https://github.com/feiskyer)) [SIG Cloud Provider]

* Move private key parsing from serviceaccount/jwt.go to client-go/util/cert ([#40907](https://github.com/kubernetes/kubernetes/pull/40907), [@cblecker](https://github.com/cblecker))
* Caching added to the OIDC client auth plugin to fix races and reduce the time kubectl commands using this plugin take by several seconds. ([#38167](https://github.com/kubernetes/kubernetes/pull/38167), [@ericchiang](https://github.com/ericchiang))

* The AWS credential provider can now obtain ECR credentials even without the AWS cloud provider or being on an EC2 instance. Additionally, AWS credential provider caching has been improved to honor the ECR credential timeout. ([#75587](https://github.com/kubernetes/kubernetes/pull/75587), [@tiffanyfay](https://github.com/tiffanyfay))

- The AWS credential provider can now obtain ECR credentials even without the AWS cloud provider or being on an EC2 instance. Additionally, AWS credential provider caching has been improved to honor the ECR credential timeout. ([#75587](https://github.com/kubernetes/kubernetes/pull/75587), [@tiffanyfay](https://github.com/tiffanyfay))


### Azure