/**
 * Implementation of {@link ImmutableSet} with two or more elements.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
@ElementTypesAreNonnullByDefault
final class RegularImmutableSet<E> extends ImmutableSet<E> {
  private static final Object[] EMPTY_ARRAY = new Object[0];

import java.util.Comparator;
import javax.annotation.CheckForNull;

/**
 * An immutable sorted multiset with one or more distinct elements.
 *
 * @author Louis Wasserman
 */
@SuppressWarnings("serial") // uses writeReplace, not default serialization
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class RegularImmutableSortedMultiset<E> extends ImmutableSortedMultiset<E> {

  public ImmutableMultiset<K> keys() {
    return (ImmutableMultiset<K>) super.keys();
  }

  @Override
  ImmutableMultiset<K> createKeys() {
    return new Keys();
  }

  @SuppressWarnings("serial") // Uses writeReplace, not default serialization
  @WeakOuter
  class Keys extends ImmutableMultiset<K> {
    @Override
    public boolean contains(@CheckForNull Object object) {
      return containsKey(object);

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

/**
 * Bimap with zero or more mappings.
 *
 * @author Louis Wasserman
 */
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
@ElementTypesAreNonnullByDefault
final class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {

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

/**
 * Unit test for {@link AbstractMultiset}.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class SimpleAbstractMultisetTest extends TestCase {
  @J2ktIncompatible
  @GwtIncompatible // suite

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

/**
 * Unit test for {@link AbstractMultiset}.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class SimpleAbstractMultisetTest extends TestCase {
  @J2ktIncompatible
  @GwtIncompatible // suite

  public ImmutableMultiset<K> keys() {
    return (ImmutableMultiset<K>) super.keys();
  }

  @Override
  ImmutableMultiset<K> createKeys() {
    return new Keys();
  }

  @SuppressWarnings("serial") // Uses writeReplace, not default serialization
  @WeakOuter
  class Keys extends ImmutableMultiset<K> {
    @Override
    public boolean contains(@CheckForNull Object object) {
      return containsKey(object);

import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@code AbstractIterator}.
 *
 * @author Kevin Bourrillion
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class AbstractIteratorTest extends TestCase {

  public void testDefaultBehaviorOfNextAndHasNext() {

 * @since 2.0 (implements {@code NavigableSet} since 12.0)
 */
// TODO(benyu): benchmark and optimize all creation paths, which are a mess now
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
public abstract class ImmutableSortedSet<E> extends ImmutableSet.CachingAsList<E>
    implements NavigableSet<E>, SortedIterable<E> {

   *         .addNode(ICELAND)
   *         .build();
   * }</pre>
   *
   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
   * multiple graphs in series. Each new graph contains all the elements of the ones created before
   * it.
   *
   * @since 28.0
   */
  public static class Builder<N> {

    private final MutableGraph<N> mutableGraph;