};
  }

  @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) {

  }

  private static Iterable<@Nullable Object> iterable(
      @Nullable Object first, @Nullable Object second, @Nullable Object[] rest) {
    checkNotNull(rest);
    return new AbstractList<@Nullable Object>() {
      @Override
      public int size() {
        return rest.length + 2;
      }

      @Override
      public @Nullable Object get(int index) {
        switch (index) {

  @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) {

  abstract <R> @Nullable R dummyReturnValue(TypeToken<R> returnType);

  private final class DummyHandler extends AbstractInvocationHandler implements Serializable {
    private final TypeToken<?> interfaceType;

    DummyHandler(TypeToken<?> interfaceType) {
      this.interfaceType = interfaceType;
    }

    @Override
    protected @Nullable Object handleInvocation(

   * there's no way to assign a {@code @Nullable T} to a field {@code T foo;} and instruct the
   * analysis that that means "plain {@code T}" rather than the inferred type {@code @Nullable T}.
   * (And even if annotations on local variables were permitted as an optional hint, no annotation
   * would be the right tool for the job here: {@code @Nullable} is the annotation that we're trying

   * there's no way to assign a {@code @Nullable T} to a field {@code T foo;} and instruct the
   * analysis that that means "plain {@code T}" rather than the inferred type {@code @Nullable T}.
   * (And even if annotations on local variables were permitted as an optional hint, no annotation
   * would be the right tool for the job here: {@code @Nullable} is the annotation that we're trying

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) {

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) {

import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * Provides static methods for working with {@link Comparator} instances. For many other helpful
 * comparator utilities, see either {@code Comparator} itself (for Java 8+), or {@code

  }

  private static <K extends @Nullable Object> @Nullable K keyOrNull(@Nullable Node<K, ?> node) {
    return node == null ? null : node.key;
  }

  private static <V extends @Nullable Object> @Nullable V valueOrNull(@Nullable Node<?, V> node) {
    return node == null ? null : node.value;
  }

  private static final class InverseSerializedForm<
          K extends @Nullable Object, V extends @Nullable Object>