- Pkg k8s.io/apiserver/pkg/storage/cacher, method (*Cacher) Wait(context.Context) error ([#125450](https://github.com/kubernetes/kubernetes/pull/125450), [@mauri870](https://github.com/mauri870)) [SIG API Machinery]

### Bug or Regression

   * default, OkHttp will perform lazy initialization upon the first usage of the cache.
   */
  @Throws(IOException::class)
  fun initialize() {
    cache.initialize()
  }

  /**
   * Closes the cache and deletes all of its stored values. This will delete all files in the cache
   * directory including files that weren't created by the cache.
   */

  long size();

  /**
   * Returns a current snapshot of this cache's cumulative statistics, or a set of default values if
   * the cache is not recording statistics. All statistics begin at zero and never decrease over the
   * lifetime of the cache.
   *
   * <p><b>Warning:</b> this cache may not be recording statistical data. For example, a cache

  long size();

  /**
   * Returns a current snapshot of this cache's cumulative statistics, or a set of default values if
   * the cache is not recording statistics. All statistics begin at zero and never decrease over the
   * lifetime of the cache.
   *
   * <p><b>Warning:</b> this cache may not be recording statistical data. For example, a cache

)

// metricsCache - cache for metrics.
//
// When serving metrics, this cache is passed to the MetricsLoaderFn.
//
// This cache is used for metrics that would result in network/storage calls.
type metricsCache struct {
	dataUsageInfo       *cachevalue.Cache[DataUsageInfo]
	esetHealthResult    *cachevalue.Cache[HealthResult]
	driveMetrics        *cachevalue.Cache[storageMetrics]

// dataUsageCacheV2 contains a cache of data usage entries version 2.
type dataUsageCacheV2 struct {
	Info  dataUsageCacheInfo
	Cache map[string]dataUsageEntryV2
}

// dataUsageCacheV3 contains a cache of data usage entries version 3.
type dataUsageCacheV3 struct {
	Info  dataUsageCacheInfo
	Cache map[string]dataUsageEntryV3
}

// dataUsageCacheV4 contains a cache of data usage entries version 4.

     * for this session, the result will be cached and subsequent identical requests will return the cached
     * value without re-executing the supplier.
     * <p>
     * The caching behavior is determined by the cache retention specified in the request's metadata.
     * If an error occurs during execution, it will be cached and re-thrown for subsequent identical requests.
     *

    for (LoadingCache<Object, Object> cache : caches()) {
      // don't let the entries get GCed
      List<Entry<Object, Object>> unused = warmUp(cache);
      assertEquals(WARMUP_SIZE, cache.size());
      assertMapSize(cache.asMap(), WARMUP_SIZE);
      checkValidState(cache);
    }
  }

  public void testContainsKey_found() {
    for (LoadingCache<Object, Object> cache : caches()) {
      // don't let the entries get GCed

    for (LoadingCache<Object, Object> cache : caches()) {
      // don't let the entries get GCed
      List<Entry<Object, Object>> unused = warmUp(cache);
      assertEquals(WARMUP_SIZE, cache.size());
      assertMapSize(cache.asMap(), WARMUP_SIZE);
      checkValidState(cache);
    }
  }

  public void testContainsKey_found() {
    for (LoadingCache<Object, Object> cache : caches()) {
      // don't let the entries get GCed

    assertThat(removalListener.getCount()).isEqualTo(1);

    // 2 will be cached
    assertThat(cache.getUnchecked(2)).isEqualTo(2);
    assertThat(cache.asMap().keySet()).containsExactly(2);

    CacheTesting.processPendingNotifications(cache);
    CacheTesting.checkValidState(cache);
    assertThat(removalListener.getCount()).isEqualTo(1);

    // 4 will be cached