* @author Louis Wasserman
 */
@GwtIncompatible // not worth using in GWT for now
@ElementTypesAreNonnullByDefault
class CompactLinkedHashSet<E extends @Nullable Object> extends CompactHashSet<E> {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * GWT emulation of {@link RegularImmutableSortedSet}.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
final class RegularImmutableSortedSet<E> extends ImmutableSortedSet<E> {

  /** true if this set is a subset of another immutable sorted set. */
  final boolean isSubset;

  private @Nullable Comparator<E> unusedComparatorForSerialization;

    @Override
    public boolean equals(@Nullable Object o) {
      return false;
    }

    @Override
    public int hashCode() {
      return super.hashCode();
    }
  }

  /** Test class that returns true if the test object is null */
  private static class InvalidEqualsNullObject {

    @Override
    public boolean equals(@Nullable Object o) {
      return o == this || o == null;
    }

              }

              @Override
              public boolean equals(@Nullable Object o) {
                return map.equals(o);
              }

              @Override
              public String toString() {
                return map.toString();
              }

              @Override
              public @Nullable String remove(Object key) {
                return map.remove(key);
              }

    InvocationHandler handler =
        new InvocationHandler() {
          @Override
          @CheckForNull
          public Object invoke(Object obj, Method method, @CheckForNull @Nullable Object[] args)
              throws Throwable {
            Callable<@Nullable Object> callable =
                () -> {
                  try {
                    return method.invoke(target, args);
                  } catch (InvocationTargetException e) {

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Transforms a value, possibly asynchronously. For an example usage and more information, see
 * {@link Futures#transformAsync(ListenableFuture, AsyncFunction, Executor)}.
 *
 * @author Chris Povirk
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface AsyncFunction<I extends @Nullable Object, O extends @Nullable Object> {
  /**

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An immutable {@code Map.Entry}, used both by {@link
 * com.google.common.collect.Maps#immutableEntry(Object, Object)} and by other parts of {@code
 * common.collect} as a superclass.
 */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
class ImmutableEntry<K extends @Nullable Object, V extends @Nullable Object>

 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class AbstractSortedKeySortedSetMultimap<
        K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractSortedSetMultimap<K, V> {

  AbstractSortedKeySortedSetMultimap(SortedMap<K, Collection<V>> map) {
    super(map);
  }

  @Override

import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Superclass for all {@code ListMultimap} testers.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@ElementTypesAreNonnullByDefault
public class AbstractListMultimapTester<K extends @Nullable Object, V extends @Nullable Object>

      Optional<String> unused =
          Optional.of("a")
              .transform(
                  (Function<String, String>)
                      new Function<String, @Nullable String>() {
                        @Override
                        public @Nullable String apply(String input) {
                          return null;
                        }
                      });
      fail("Should throw if Function returns null.");