@Override
  public <T extends B> @Nullable T putInstance(
      Class<@NonNull T> type, @ParametricNullness T value) {
    return cast(type, put(type, value));
  }

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(Class<T> type) {
    return cast(type, get(type));
  }

  @CanIgnoreReturnValue
  private static <T> @Nullable T cast(Class<T> type, @Nullable Object value) {

  }

  private static final class TestCallable implements AsyncCallable<@Nullable Void> {

    private final ListenableFuture<@Nullable Void> future;
    private boolean called = false;

    private TestCallable(ListenableFuture<@Nullable Void> future) {
      this.future = future;
    }

    @Override
    public ListenableFuture<@Nullable Void> call() throws Exception {
      called = true;
      return future;

  @VisibleForTesting final transient @Nullable Object[] elements;
  private final transient int hashCode;
  // the same values as `elements` in hashed positions (plus nulls)
  @VisibleForTesting final transient @Nullable Object[] table;
  // 'and' with an int to get a valid table index.
  private final transient int mask;
  private final transient int size;

  RegularImmutableSet(

  private static class UnmodifiableMultimap<K extends @Nullable Object, V extends @Nullable Object>
      extends ForwardingMultimap<K, V> implements Serializable {
    final Multimap<K, V> delegate;
    @LazyInit transient @Nullable Collection<Entry<K, V>> entries;
    @LazyInit transient @Nullable Multiset<K> keys;
    @LazyInit transient @Nullable Set<K> keySet;
    @LazyInit transient @Nullable Collection<V> values;

  private static class UnmodifiableMultimap<K extends @Nullable Object, V extends @Nullable Object>
      extends ForwardingMultimap<K, V> implements Serializable {
    final Multimap<K, V> delegate;
    @LazyInit transient @Nullable Collection<Entry<K, V>> entries;
    @LazyInit transient @Nullable Multiset<K> keys;
    @LazyInit transient @Nullable Set<K> keySet;
    @LazyInit transient @Nullable Collection<V> values;

          .buildOrThrow();

  @VisibleForTesting @Nullable Integer initialCapacity;
  @VisibleForTesting @Nullable Long maximumSize;
  @VisibleForTesting @Nullable Long maximumWeight;
  @VisibleForTesting @Nullable Integer concurrencyLevel;
  @VisibleForTesting @Nullable Strength keyStrength;
  @VisibleForTesting @Nullable Strength valueStrength;
  @VisibleForTesting @Nullable Boolean recordStats;

          .buildOrThrow();

  @VisibleForTesting @Nullable Integer initialCapacity;
  @VisibleForTesting @Nullable Long maximumSize;
  @VisibleForTesting @Nullable Long maximumWeight;
  @VisibleForTesting @Nullable Integer concurrencyLevel;
  @VisibleForTesting @Nullable Strength keyStrength;
  @VisibleForTesting @Nullable Strength valueStrength;
  @VisibleForTesting @Nullable Boolean recordStats;

  public void testTransformEntrySetContains() {
    Map<@Nullable String, @Nullable Boolean> underlying = new HashMap<>();
    underlying.put("a", null);
    underlying.put("b", true);
    underlying.put(null, true);

    Map<@Nullable String, @Nullable Boolean> map =
        transformValues(
            underlying,
            new Function<@Nullable Boolean, @Nullable Boolean>() {
              @Override

  @Generates
  static <K, V> Map<K, V> generateMap(@Nullable K key, @Nullable V value) {
    return generateHashdMap(key, value);
  }

  @Generates
  static <K, V> HashMap<K, V> generateHashdMap(@Nullable K key, @Nullable V value) {
    return generateLinkedHashMap(key, value);
  }

  @Generates
  static <K, V> LinkedHashMap<K, V> generateLinkedHashMap(@Nullable K key, @Nullable V value) {

  private static final Iterable<@Nullable Integer> iterableNull = Arrays.asList((Integer) null);
  private static final Iterable<@Nullable Integer> iterableNullNull =
      Arrays.asList((Integer) null, null);
  private static final Iterable<@Nullable Integer> iterableNull1 = Arrays.asList(null, 1);
  private static final Iterable<@Nullable Integer> iterable1Null = Arrays.asList(1, null);