CacheTesting.processPendingNotifications(cache);
    assertEquals(1, cache.size());
    assertEquals(1, removalListener.getCount());
  }

  // A simple type whose .toString() will return the same value each time, but without maintaining
  // a strong reference to that value.
  static class Key {
    private final int value;
    private WeakReference<String> toString;

    Key(int value) {
      this.value = value;

This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

## Second dependency, "dependable" and "dependant"

Then you can create another dependency function (a "dependable") that at the same time declares a dependency of its own (so it is a "dependant" too):

//// tab | Python 3.10+

```Python hl_lines="13"
{!> ../../docs_src/dependencies/tutorial005_an_py310.py!}
```

////

//// tab | Python 3.9+

  val path: Path = PUBLIC_SUFFIX_RESOURCE,
  val fileSystem: FileSystem = FileSystem.RESOURCES,
) {
  /** True after we've attempted to read the list for the first time. */
  private val listRead = AtomicBoolean(false)

  /** Used for concurrent threads reading the list for the first time. */
  private val readCompleteLatch = CountDownLatch(1)

  // The lists are held as a large array of UTF-8 bytes. This is to avoid allocating lots of strings

  }

  /**
   * Sends the given method call to this thread.
   *
   * @throws TimeoutException if this thread does not accept the request within a reasonable amount
   *     of time
   */
  private void sendRequest(String methodName, Object... arguments) throws Exception {
    if (!requestQueue.offer(new Request(methodName, arguments), TIMEOUT_MILLIS, MILLISECONDS)) {
      throw new TimeoutException();

    return new MinimalIterable<>(asList(elements).iterator());
  }

  /**
   * Returns an iterable whose iterator returns the given elements in order. The elements are copied
   * out of the source collection at the time this method is called.
   */
  @SuppressWarnings("unchecked") // Es come in, Es go out
  public static <E extends @Nullable Object> MinimalIterable<E> from(Collection<E> elements) {

You send it a token and it returns an authenticated user.

This provider might be charging you per request, and calling it might take some extra time than if you had a fixed mock user for tests.

You probably want to test the external provider once, but not necessarily call it for every test that runs.

            protected void printByLtsv(final Map<String, String> valueMap) {
                valueMap.remove("time");
                valueMap.remove("ip");
                super.printByLtsv(valueMap);
            }

            @Override
            protected void printByEcs(final Map<String, String> valueMap) {
                valueMap.put("time", "2022-01-01T00:00:00.000Z");
                valueMap.remove("ip");

   * key, the choice of {@link KeyAbsentBehavior} decides which index is returned.
   *
   * <p>This method runs in log(n) time on random-access lists, which offer near-constant-time
   * access to each list element.
   *
   * @param list the list to be searched.
   * @param key the value to be searched for.
   * @param comparator the comparator by which the list is ordered.

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.es.config.bsentity;

import java.time.LocalDateTime;
import java.util.HashMap;
import java.util.Map;

import org.codelibs.fess.es.config.allcommon.EsAbstractEntity;
import org.codelibs.fess.es.config.bsentity.dbmeta.ThumbnailQueueDbm;

/**

    }
    entry = cacheEntry2;
    if (entry != null && entry.key == key) {
      // Promote second cache entry to first so the access pattern
      // [K1, K2, K1, K3, K1, K4...] still hits the cache half the time.
      addToCache(entry);
      return entry.value;
    }
    return null;
  }

  @Override
  void clearCache() {
    super.clearCache();
    cacheEntry1 = null;
    cacheEntry2 = null;
  }