import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/** An ordering that treats {@code null} as less than all other values. */
@GwtCompatible
final class NullsFirstOrdering<T extends @Nullable Object> extends Ordering<@Nullable T>
    implements Serializable {
  final Ordering<? super T> ordering;

  NullsFirstOrdering(Ordering<? super T> ordering) {
    this.ordering = ordering;
  }

  @Override

import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/** An ordering that treats {@code null} as greater than all other values. */
@GwtCompatible
final class NullsLastOrdering<T extends @Nullable Object> extends Ordering<@Nullable T>
    implements Serializable {
  final Ordering<? super T> ordering;

  NullsLastOrdering(Ordering<? super T> ordering) {
    this.ordering = ordering;
  }

  @Override

import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/** An ordering that treats {@code null} as greater than all other values. */
@GwtCompatible
final class NullsLastOrdering<T extends @Nullable Object> extends Ordering<@Nullable T>
    implements Serializable {
  final Ordering<? super T> ordering;

  NullsLastOrdering(Ordering<? super T> ordering) {
    this.ordering = ordering;
  }

  @Override

     * operation O(1).
     */

    private @Nullable Iterator<? extends Iterator<? extends T>> topMetaIterator;

    // Only becomes nonnull if we encounter nested concatenations.
    private @Nullable Deque<Iterator<? extends Iterator<? extends T>>> metaIterators;

    ConcatenatedIterator(Iterator<? extends Iterator<? extends T>> metaIterator) {
      iterator = emptyIterator();

     * operation O(1).
     */

    private @Nullable Iterator<? extends Iterator<? extends T>> topMetaIterator;

    // Only becomes nonnull if we encounter nested concatenations.
    private @Nullable Deque<Iterator<? extends Iterator<? extends T>>> metaIterators;

    ConcatenatedIterator(Iterator<? extends Iterator<? extends T>> metaIterator) {
      iterator = emptyIterator();

    abstract class Retailer<ProductT> extends Shop<ProductT>
        implements Comparator<ProductT>, ConsumerFacing<ProductT> {}
  }

  private static class Outlet<T> extends Mall<T> {}

  private interface UseIterable<T extends Iterable<?>> {}

  private interface UseSerializableIterable<T extends Serializable & Iterable<?>> {}

  private interface UseList<T extends List<?>> {}

  private enum MyEnum {}

 *
 * @author Hayward Chan
 */
final class Platform {
  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> newHashMapWithExpectedSize(int expectedSize) {
    return Maps.newHashMapWithExpectedSize(expectedSize);
  }

  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> newLinkedHashMapWithExpectedSize(int expectedSize) {

     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      requireNonNull(contents); // see the comment on the field
      if (elements instanceof Multiset) {
        Multiset<? extends E> multiset = (Multiset<? extends E>) elements;
        ObjectCountHashMap<? extends E> backingMap = tryGetMap(multiset);
        if (backingMap != null) {

  }

  static final class ImmediateFailedFuture<V extends @Nullable Object> extends TrustedFuture<V> {
    ImmediateFailedFuture(Throwable thrown) {
      setException(thrown);
    }
  }

  static final class ImmediateCancelledFuture<V extends @Nullable Object> extends TrustedFuture<V> {
    static final @Nullable ImmediateCancelledFuture<Object> INSTANCE =

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public abstract class AbstractMultimapTester<
        K extends @Nullable Object, V extends @Nullable Object, M extends Multimap<K, V>>
    extends AbstractContainerTester<M, Entry<K, V>> {

  private M multimap;

  protected M multimap() {
    return multimap;
  }

  /**