/** The HTTP {@code Refresh} header field name. Non-standard header supported by most browsers. */
  public static final String REFRESH = "Refresh";

  /**
   * The HTTP <a href="https://www.w3.org/TR/reporting/">{@code Report-To}</a> header field name.
   *
   * @since 27.1
   */
  public static final String REPORT_TO = "Report-To";

  /** The HTTP {@code Retry-After} header field name. */

### Bug or Regression

- Disable aufs module for gce clusters ([#103831](https://github.com/kubernetes/kubernetes/pull/103831), [@lizhuqi](https://github.com/lizhuqi)) [SIG Cloud Provider]
- Fix kube-apiserver metric reporting for the deprecated watch path of /api/<version>/watch/... ([#104191](https://github.com/kubernetes/kubernetes/pull/104191), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery and Instrumentation]

* Fix inconsistent Prometheus cAdvisor metrics ([#51473](https://github.com/kubernetes/kubernetes/pull/51473), [@bboreham](https://github.com/bboreham))
* Fixed an issue reporting lack of progress for a deployment prematurely ([#52178](https://github.com/kubernetes/kubernetes/pull/52178), [@kargakis](https://github.com/kargakis))

- Added two client certificate metrics for exec auth:
    - `rest_client_certificate_expiration_seconds` a gauge reporting the lifetime of the current client certificate. Reports the time of expiry in seconds since January 1, 1970 UTC.

- Removed general available feature-gate `PDBUnhealthyPodEvictionPolicy`. ([#129500](https://github.com/kubernetes/kubernetes/pull/129500), [@carlory](https://github.com/carlory)) [SIG API Machinery, Apps and Auth]
- Start reporting swap capacity as part of `node.status.nodeSystemInfo`. ([#129954](https://github.com/kubernetes/kubernetes/pull/129954), [@iholder101](https://github.com/iholder101)) [SIG API Machinery, Apps and Node]

* fix race condition when attach azure disk in vmss ([#71992](https://github.com/kubernetes/kubernetes/pull/71992), [@andyzhangx](https://github.com/andyzhangx))
* Fixed kubelet reporting "resource name may not be empty" when mounting a volume very quickly after unmount. ([#71074](https://github.com/kubernetes/kubernetes/pull/71074), [@jsafrane](https://github.com/jsafrane))

* Set node external IP for azure node when disabling UseInstanceMetadata ([#60959](https://github.com/kubernetes/kubernetes/pull/60959), [@feiskyer](https://github.com/feiskyer))
* [fluentd-gcp addon] Fixed bug with reporting metrics in event-exporter ([#60126](https://github.com/kubernetes/kubernetes/pull/60126), [@serathius](https://github.com/serathius))

    return entryHelper.valueStrength().defaultEquivalence();
  }

  // ConcurrentMap methods

  @Override
  public boolean isEmpty() {
    /*
     * Sum per-segment modCounts to avoid mis-reporting when elements are concurrently added and
     * removed in one segment while checking another, in which case the table was never actually
     * empty at any point. (The sum ensures accuracy up through at least 1<<31 per-segment

### Bug or Regression

- Disable aufs module for gce clusters ([#103831](https://github.com/kubernetes/kubernetes/pull/103831), [@lizhuqi](https://github.com/lizhuqi)) [SIG Cloud Provider]
- Fix kube-apiserver metric reporting for the deprecated watch path of /api/<version>/watch/... ([#104190](https://github.com/kubernetes/kubernetes/pull/104190), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery and Instrumentation]

- Kubelet: Added kubelet serving certificate metric `server_rotation_seconds` which is a histogram reporting the age of a just rotated serving certificate in seconds. ([#84534](https://github.com/kubernetes/kubernetes/pull/84534), [@sambdavidson](https://github.com/sambdavidson))