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) {

  // TODO: b/287198172 - Consider eagerly initializing these (but think about serialization).
  @LazyInit private transient @Nullable Ordering<@Nullable Comparable<?>> nullsFirst;
  @LazyInit private transient @Nullable Ordering<@Nullable Comparable<?>> nullsLast;

  @Override
  @SuppressWarnings("unchecked") // TODO(kevinb): the right way to explain this??
  public int compare(Comparable<?> left, Comparable<?> right) {

import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Objects;
import org.jspecify.annotations.Nullable;

/**
 * Implementation for {@link FilteredMultimap#values()}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredMultimapValues<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractCollection<V> {
  @Weak private final FilteredMultimap<K, V> multimap;

  @CanIgnoreReturnValue
  @Override
  public @Nullable V putIfAbsent(K key, V value) {
    return delegate().putIfAbsent(key, value);
  }

  @CanIgnoreReturnValue
  @Override
  public boolean remove(@Nullable Object key, @Nullable Object value) {
    return delegate().remove(key, value);
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V replace(K key, V value) {

  @VisibleForTesting final transient @Nullable Object[] array;
  private final transient int size;

  RegularImmutableList(@Nullable Object[] array, int size) {
    this.array = array;
    this.size = size;
  }

  @Override
  public int size() {
    return size;
  }

  @Override
  boolean isPartialView() {
    return false;
  }

  @Override
  @Nullable Object[] internalArray() {
    return array;

  @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) {

    };
  }

  @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) {

import java.util.concurrent.ConcurrentHashMap;
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) {

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(Class<T> type) {
    return trustedGet(TypeToken.of(type));
  }

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(TypeToken<T> type) {
    return trustedGet(type.rejectTypeVariables());
  }

  @Override
  @CanIgnoreReturnValue
  public <T extends B> @Nullable T putInstance(

  }

  @ParametricNullness
  private <T extends @Nullable Object> T callWithTimeout(
      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit, boolean amInterruptible)
      throws Exception {
    checkNotNull(callable);
    checkNotNull(timeoutUnit);
    checkPositiveTimeout(timeoutDuration);

    Future<T> future = executor.submit(callable);

    try {
      return amInterruptible