import org.opensearch.transport.client.AdminClient;
import org.opensearch.transport.client.Client;
import org.opensearch.transport.client.ClusterAdminClient;

/**
 * Test class for FesenClient to verify improvements made to the implementation.
 */
public class FesenClientTest {

    private static final Logger logger = LogManager.getLogger(FesenClientTest.class);

    private FesenClient fesenClient;

    </dependency>
    ```

 *  **New APIs to permit easy certificate pinning.** Be warned, certificate
    pinning is dangerous and could prevent your application from trusting your
    server!

 *  **Cache improvements.** This release fixes some severe cache problems
    including a bug where the cache could be corrupted upon certain access
    patterns. We also fixed a bug where the cache was being cleared due to a

In this release the SIG again focused on further improving the user experience on cluster creation and also fixing a number of bugs and other assorted improvements.

Some notable changes in kubeadm since Kubernetes 1.12:

   * to prove its primality. Values from miller-rabin.appspot.com.
   *
   * NOTE: We could get slightly better bases that would be treated as unsigned, but benchmarks
   * showed negligible performance improvements.
   */
  private static final long[][] millerRabinBaseSets = {
    {291830, 126401071349994536L},
    {885594168, 725270293939359937L, 3569819667048198375L},

  - Some kubeadm commands are now allowed to work in a completely offline mode.
- Certificate handling improvements:
  - Renew certs as part of upgrade.
  - New `kubeadm alpha phase certs renew` command for renewing certificates.
  - Certificates created with kubeadm now have improved uniqueness of Distinguished Name fields.
- HA improvements:

    * action required: users deploying workloads with priority lower than 0 may want to use priority lower than -10 to avoid triggering scale-up.

### Other notable changes

* Metadata Agent Improvements ([#66485](https://github.com/kubernetes/kubernetes/pull/66485), [@bmoyles0117](https://github.com/bmoyles0117))
    * Bump metadata agent version to 0.2-0.0.21-1.
    * Expand the metadata agent's access to all API groups.

    - [CustomResourceDefinition OpenAPI Publishing](#customresourcedefinition-openapi-publishing)
  - [Cluster Lifecycle Stability and Usability Improvements](#cluster-lifecycle-stability-and-usability-improvements)
  - [Continued improvement of CSI](#continued-improvement-of-csi)
    - [Additional Notable Feature Updates](#additional-notable-feature-updates)
  - [Known Issues](#known-issues)

### Auth

* Metadata Agent Improvements ([#66485](https://github.com/kubernetes/kubernetes/pull/66485), [@bmoyles0117](https://github.com/bmoyles0117))
    * Bump metadata agent version to 0.2-0.0.21-1.
    * Expand the metadata agent's access to all API groups.

- Kubeadm: apply further improvements to the tentative support for concurrent etcd member join. Fixes a bug where multiple members can receive the same hostname. Increase the etcd client dial timeout and retry timeout for add/remove/... operations. ([#87505](https://github.com/kub...