* 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.
   */

- 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

    for (LoadingCache<Object, Object> cache : caches()) {
      // don't let the entries get GCed
      List<Entry<Object, Object>> unused = warmUp(cache);
      assertThat(cache.size()).isEqualTo(WARMUP_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);
      assertThat(cache.size()).isEqualTo(WARMUP_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

    for (LoadingCache<Key, String> cache : caches()) {
      Key key = new Key(1);
      String value = key.toString();
      assertThat(cache.getUnchecked(key)).isSameInstanceAs(value);
      assertThat(cache.asMap().isEmpty()).isFalse();
      cache.invalidateAll();
      assertThat(cache.size()).isEqualTo(0);
      assertThat(cache.asMap().isEmpty()).isTrue();
      assertThat(cache.asMap().containsKey(key)).isFalse();

  // 1. successful fresh cached GET response
  // 2. unsuccessful (404, 500) fresh cached GET response
  // 3. successful network response
  // 4. successful stale cached GET response
  // 5. unsuccessful response
  @Test
  fun usesCache() {
    val cache = Cache(cacheFs, "cache".toPath(), (100 * 1024).toLong())
    val cachedClient = bootstrapClient.newBuilder().cache(cache).build()

 * by the garbage collector. Entries with reclaimed keys or values may be removed from the cache on
 * each cache modification, on occasional cache accesses, or on calls to {@link Cache#cleanUp}; such
 * entries may be counted in {@link Cache#size}, but will never be visible to read or write
 * operations.
 *

    for (LoadingCache<Key, String> cache : caches()) {
      Key key = new Key(1);
      String value = key.toString();
      assertThat(cache.getUnchecked(key)).isSameInstanceAs(value);
      assertThat(cache.asMap().isEmpty()).isFalse();
      cache.invalidateAll();
      assertThat(cache.size()).isEqualTo(0);
      assertThat(cache.asMap().isEmpty()).isTrue();
      assertThat(cache.asMap().containsKey(key)).isFalse();

    // Cause the rebuild action to fail.
    filesystem.setFaultyRename(cacheDir / DiskLruCache.JOURNAL_FILE_BACKUP, true)
    taskFaker.runNextTask()

    // The rebuild is retried on cache hits and on cache edits.
    val snapshot = cache["b"]!!
    snapshot.close()
    assertThat(cache.edit("d")).isNull()
    assertThat(taskFaker.isIdle()).isFalse()

    // On cache misses, no retry job is queued.
    assertThat(cache["c"]).isNull()