*/
  public static <A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      Function<A, C> compose(Function<B, C> g, Function<A, ? extends B> f) {
    return new FunctionComposition<>(g, f);
  }

  private static final class FunctionComposition<
          A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      implements Function<A, C>, Serializable {

  public void testAsMap() {
    CacheBuilder<Object, Object> builder = createCacheBuilder();
    LocalLoadingCache<Object, Object> cache = makeCache(builder, identityLoader());
    assertThat(cache.stats()).isEqualTo(EMPTY_STATS);

    Object one = new Object();
    Object two = new Object();
    Object three = new Object();

    ConcurrentMap<Object, Object> map = cache.asMap();
    assertThat(map.put(one, two)).isNull();

  public void testAsMap() {
    CacheBuilder<Object, Object> builder = createCacheBuilder();
    LocalLoadingCache<Object, Object> cache = makeCache(builder, identityLoader());
    assertThat(cache.stats()).isEqualTo(EMPTY_STATS);

    Object one = new Object();
    Object two = new Object();
    Object three = new Object();

    ConcurrentMap<Object, Object> map = cache.asMap();
    assertThat(map.put(one, two)).isNull();

```sh
aws s3api put-object --bucket testbucket --key lockme --object-lock-mode GOVERNANCE --object-lock-retain-until-date "2019-11-20"  --body /etc/issue
```

See <https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lock-overview.html> for AWS S3 spec on object locking and permissions required for object retention and governance bypass overrides.

### Set legal hold on an object

    Object one = new Object();
    Object two = new Object();
    CacheLoader<Object, Object> loader =
        new CacheLoader<Object, Object>() {
          @Override
          public Object load(Object key) {
            return one;
          }

          @Override
          public ListenableFuture<Object> reload(Object key, Object oldValue) {
            return immediateFuture(two);

        Object result = data.getDataMap().get("entities");
        assertNotNull(result);
        assertTrue(result instanceof List);
        @SuppressWarnings("unchecked")
        List<Map<String, Object>> resultList = (List<Map<String, Object>>) result;
        assertEquals(2, resultList.size());

        Map<String, Object> map1 = resultList.get(0);

  @Override
  protected boolean standardContains(@Nullable Object object) {
    try {
      // any ClassCastExceptions and NullPointerExceptions are caught
      @SuppressWarnings({"unchecked", "nullness"})
      SortedSet<@Nullable Object> self = (SortedSet<@Nullable Object>) this;
      Object ceiling = self.tailSet(object).first();
      return unsafeCompare(comparator(), ceiling, object) == 0;

    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Entry<Object, Object>> entries = cache.asMap().entrySet();
      assertThrows(
          NullPointerException.class, () -> entries.toArray((Entry<Object, Object>[]) null));
      checkEmpty(cache);
    }
  }

  public void testEntrySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(

    final List<Object> annotatedIn1And2AndClassEvents = new ArrayList<>();
    final List<Object> declaredIn1AnnotatedIn2Events = new ArrayList<>();
    final List<Object> declaredIn1AnnotatedInClassEvents = new ArrayList<>();
    final List<Object> declaredIn2AnnotatedInClassEvents = new ArrayList<>();
    final List<Object> annotatedIn2Events = new ArrayList<>();

        assertFalse(docMap.isEmpty());

        Set<Map.Entry<String, Object>> actual = docMap.entrySet();
        assertTrue(actual.size() == keys.size());
        docMap.clear();

        assertTrue(docMap.isEmpty());
    }

    @Test
    public void test_constructor() {
        Map<String, Object> parentMap = new HashMap<>();
        DocMap docMap = new DocMap(parentMap);