}

  /**
   * Returns a {@code new Object()} for every request, and increments a counter for every request.
   * The count is accessible via {@link #getCount}.
   */
  static class CountingLoader extends CacheLoader<Object, Object> {
    private final AtomicInteger count = new AtomicInteger();

    @Override
    public Object load(Object from) {
      count.incrementAndGet();
      return new Object();

    SettableFuture<String> settable = SettableFuture.create();
    ListenableFuture<?> f = settable;
    FutureCallback<@Nullable Object> callback =
        new FutureCallback<@Nullable Object>() {
          @Override
          public void onSuccess(@Nullable Object result) {}

          @Override
          public void onFailure(Throwable t) {}
        };
    addCallback(f, callback, directExecutor());
  }

	usageVersionsCountMD = NewGaugeMD(usageVersionsCount,
		"Total cluster object versions (including delete markers) count")
	usageDeleteMarkersCountMD = NewGaugeMD(usageDeleteMarkersCount,
		"Total cluster delete markers count")
	usageBucketsCountMD = NewGaugeMD(usageBucketsCount,
		"Total cluster buckets count")
	usageObjectsDistributionMD = NewGaugeMD(usageSizeDistribution,
		"Cluster object size distribution", "range")

    //                                                                              ======
    @Override
    public Map<String, Object> toSource() {
        Map<String, Object> sourceMap = new HashMap<>();
        if (createdAt != null) {
            addFieldToSource(sourceMap, "createdAt", createdAt);
        }
        if (docId != null) {

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public abstract class AbstractBiMapTester<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMapTester<K, V> {

  @Override
  protected BiMap<K, V> getMap() {
    return (BiMap<K, V>) super.getMap();
  }

  static <K extends @Nullable Object, V extends @Nullable Object> Entry<V, K> reverseEntry(
      Entry<K, V> entry) {
    return mapEntry(entry.getValue(), entry.getKey());

  Set<EndpointPair<N>> edges();

  /**
   * Returns an {@link ElementOrder} that specifies the order of iteration for the elements of
   * {@link #edges()}, {@link #adjacentNodes(Object)}, {@link #predecessors(Object)}, {@link
   * #successors(Object)} and {@link #incidentEdges(Object)}.
   *
   * @since 29.0
   */
  ElementOrder<N> incidentEdgeOrder();

  /**

    return (index >= 0 && get(index).equals(target)) ? index : -1;
  }

  @GwtIncompatible // ImmutableSortedSet.indexOf
  @Override
  public int lastIndexOf(@Nullable Object target) {
    return indexOf(target);
  }

  @Override
  public boolean contains(@Nullable Object target) {
    // Necessary for ISS's with comparators inconsistent with equals.
    return indexOf(target) >= 0;
  }

     * @param key The key to use associate the data with, must not be {@code null}.
     * @param data The data to store in the cache, may be {@code null}.
     */
    void put(RepositoryRequest request, Object key, Object data);

    /**
     * Gets the specified data from the cache. <strong>Warning:</strong> The cache will directly return the saved

  }

  public void testConstant() {
    Function<@Nullable Object, Object> f = Functions.<Object>constant("correct");
    assertEquals("correct", f.apply(new Object()));
    assertEquals("correct", f.apply(null));

    Function<@Nullable Object, @Nullable String> g = Functions.constant(null);
    assertThat(g.apply(2)).isNull();
    assertThat(g.apply(null)).isNull();

          .sampleValues();
    }

    @Override
    public Collection<V> create(Object... elements) {
      K k =
          ((TestMultimapGenerator<K, V, M>) multimapGenerator.getInnerGenerator())
              .sampleKeys()
              .e0();
      Object[] entries = new Object[elements.length];
      for (int i = 0; i < elements.length; i++) {