if (map instanceof ImmutableClassToInstanceMap) {
      @SuppressWarnings("rawtypes") // JDT-based J2KT Java frontend does not permit the direct cast
      Map rawMap = map;
      @SuppressWarnings("unchecked") // covariant casts safe (unmodifiable)
      ImmutableClassToInstanceMap<B> cast = (ImmutableClassToInstanceMap<B>) rawMap;
      return cast;
    }
    return new Builder<B>().putAll(map).build();
  }

  protected List<TestSuite> createDerivedSuites(
      FeatureSpecificTestSuiteBuilder<
              ?, ? extends OneSizeTestContainerGenerator<Map<K, V>, Entry<K, V>>>
          parentBuilder) {
    // TODO: Once invariant support is added, supply invariants to each of the
    // derived suites, to check that mutations to the derived collections are
    // reflected in the underlying map.

  }

  /**
   * Returns the empty immutable multiset.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked") // all supported methods are covariant
  public static <E> ImmutableMultiset<E> of() {
    return (ImmutableMultiset<E>) RegularImmutableMultiset.EMPTY;
  }

  /**
   * Returns an immutable multiset containing a single element.
   *

    UnmodifiableTable(Table<? extends R, ? extends C, ? extends V> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @SuppressWarnings("unchecked") // safe, covariant cast
    @Override
    protected Table<R, C, V> delegate() {
      return (Table<R, C, V>) delegate;
    }

    @Override
    public Set<Cell<R, C, V>> cellSet() {

   */
  public static <E> ImmutableList<E> copyOf(Collection<? extends E> elements) {
    if (elements instanceof ImmutableCollection) {
      @SuppressWarnings("unchecked") // all supported methods are covariant
      ImmutableList<E> list = ((ImmutableCollection<E>) elements).asList();
      return list.isPartialView() ? ImmutableList.<E>asImmutableList(list.toArray()) : list;
    }
    return construct(elements.toArray());

 * href="https://github.com/google/guava/wiki/UsingAndAvoidingNullExplained#optional">using {@code
 * Optional}</a>.
 *
 * @param <T> the type of instance that can be contained. {@code Optional} is naturally covariant on
 *     this type, so it is safe to cast an {@code Optional<T>} to {@code Optional<S>} for any
 *     supertype {@code S} of {@code T}.
 * @author Kurt Alfred Kluever
 * @author Kevin Bourrillion
 * @since 10.0
 */

   * array with a nullable element type. But probably they usually want an array with a non-nullable
   * type. That said, we could *accept* a `@Nullable T[]` (which, given that we treat arrays as
   * covariant, would still permit a plain `T[]`) and return a plain `T[]`. But of course that would
   * require its own suppression, since it is also unsound. toArray(T[]) is just a mess from a

  }

  @Override
  protected List<TestSuite> createDerivedSuites(
      FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<M, Entry<K, V>>>
          parentBuilder) {
    // TODO: Once invariant support is added, supply invariants to each of the
    // derived suites, to check that mutations to the derived collections are
    // reflected in the underlying map.

   * array with a nullable element type. But probably they usually want an array with a non-nullable
   * type. That said, we could *accept* a `@Nullable T[]` (which, given that we treat arrays as
   * covariant, would still permit a plain `T[]`) and return a plain `T[]`. But of course that would
   * require its own suppression, since it is also unsound. toArray(T[]) is just a mess from a

      Iterator<? extends T> iterator) {
    checkNotNull(iterator);
    if (iterator instanceof UnmodifiableIterator) {
      @SuppressWarnings("unchecked") // Since it's unmodifiable, the covariant cast is safe
      UnmodifiableIterator<T> result = (UnmodifiableIterator<T>) iterator;
      return result;
    }
    return new UnmodifiableIterator<T>() {
      @Override
      public boolean hasNext() {