@GwtIncompatible // not worth using in GWT for now
final class CompactLinkedHashMap<K extends @Nullable Object, V extends @Nullable Object>
    extends CompactHashMap<K, V> {
  // TODO(lowasser): implement removeEldestEntry so this can be used as a drop-in replacement

  /** Creates an empty {@code CompactLinkedHashMap} instance. */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      CompactLinkedHashMap<K, V> create() {

import org.jspecify.annotations.Nullable;

/**
 * Tests for {@code AbstractMapEntry}.
 *
 * @author Mike Bostock
 */
@GwtCompatible
@NullMarked
public class AbstractMapEntryTest extends TestCase {
  private static final @Nullable String NK = null;
  private static final @Nullable Integer NV = null;

  private static <K extends @Nullable Object, V extends @Nullable Object> Entry<K, V> entry(
      K key, V value) {

    private static final AtomicReferenceFieldUpdater<Waiter, @Nullable Thread> waiterThreadUpdater =
        AtomicReferenceFieldUpdater.<Waiter, @Nullable Thread>newUpdater(
            Waiter.class, Thread.class, "thread");
    private static final AtomicReferenceFieldUpdater<Waiter, @Nullable Waiter> waiterNextUpdater =
        AtomicReferenceFieldUpdater.<Waiter, @Nullable Waiter>newUpdater(
            Waiter.class, Waiter.class, "next");

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

@GwtCompatible
@NullMarked
public class Helpers {
  // Clone of Objects.equals
  static boolean equal(@Nullable Object a, @Nullable Object b) {
    return a == b || (a != null && a.equals(b));
  }

  // Clone of Lists.newArrayList
  public static <E extends @Nullable Object> List<E> copyToList(Iterable<? extends E> elements) {

import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * GWT emulated version of {@link ImmutableList}. TODO(cpovirk): more doc
 *
 * @author Hayward Chan
 */
abstract class ForwardingImmutableList<E> extends ImmutableList<E> {

  ForwardingImmutableList() {}

  abstract List<E> delegateList();

  @Override
  public int indexOf(@Nullable Object object) {
    return delegateList().indexOf(object);

   */
  @Override
  public boolean containsValue(@Nullable Object value) {
    return findEntryByValue(value) != ABSENT;
  }

  @Override
  public @Nullable V get(@Nullable Object key) {
    int entry = findEntryByKey(key);
    return (entry == ABSENT) ? null : values[entry];
  }

  @Nullable K getInverse(@Nullable Object value) {
    int entry = findEntryByValue(value);

import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Methods factored out so that they can be emulated differently in GWT.
 *
 * @author Hayward Chan
 */
@GwtCompatible
final class Platform {
  /** Returns the platform preferred implementation of a map based on a hash table. */
  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> newHashMapWithExpectedSize(int expectedSize) {

          <item index="2" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNullable" />
          <item index="3" class="java.lang.String" itemvalue="com.android.annotations.Nullable" />
          <item index="4" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
          <item index="5" class="java.lang.String" itemvalue="io.reactivex.annotations.Nullable" />

    };
  }

  @Override
  public @Nullable Entry<K, V> firstEntry() {
    return delegate.firstEntry();
  }

  @Override
  public K firstKey() {
    return delegate.firstKey();
  }

  @Override
  public @Nullable Entry<K, V> floorEntry(K key) {
    return delegate.floorEntry(checkValid(key));
  }

  @Override
  public @Nullable K floorKey(K key) {

    public @Nullable V floor(@ParametricNullness V v) {
      return getSortedSetDelegate().floor(v);
    }

    @Override
    public @Nullable V ceiling(@ParametricNullness V v) {
      return getSortedSetDelegate().ceiling(v);
    }

    @Override
    public @Nullable V higher(@ParametricNullness V v) {
      return getSortedSetDelegate().higher(v);
    }

    @Override
    public @Nullable V pollFirst() {