*
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingIterator<T extends @Nullable Object> extends ForwardingObject
    implements Iterator<T> {

  /** Constructor for use by subclasses. */
  protected ForwardingIterator() {}

  @Override
  protected abstract Iterator<T> delegate();

  @Override
  public boolean hasNext() {
    return delegate().hasNext();

 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible
public abstract class ForwardingSetMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends ForwardingMultimap<K, V> implements SetMultimap<K, V> {
  /** Constructor for use by subclasses. */
  public ForwardingSetMultimap() {}

  @Override
  protected abstract SetMultimap<K, V> delegate();

  @Override
  public Set<Entry<K, V>> entries() {

import com.google.common.annotations.J2ktIncompatible;
import java.util.Spliterator;
import java.util.function.Consumer;
import org.jspecify.annotations.Nullable;

@GwtCompatible
abstract class IndexedImmutableSet<E> extends ImmutableSet.CachingAsList<E> {
  abstract E get(int index);

  @Override
  public UnmodifiableIterator<E> iterator() {
    return asList().iterator();
  }

  @Override
  public Spliterator<E> spliterator() {

 *
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingQueue<E extends @Nullable Object> extends ForwardingCollection<E>
    implements Queue<E> {

  /** Constructor for use by subclasses. */
  protected ForwardingQueue() {}

  @Override
  protected abstract Queue<E> delegate();

  @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
  @Override

import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import org.jspecify.annotations.Nullable;

/**
 * An abstract implementation of {@link Hasher}, which only requires subtypes to implement {@link
 * #putByte}. Subtypes may provide more efficient implementations, however.
 *
 * @author Dimitris Andreou
 */
abstract class AbstractHasher implements Hasher {
  @Override
  @CanIgnoreReturnValue

import org.jspecify.annotations.NullMarked;

/**
 * Generates {@code List<Character>} instances for test suites.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public abstract class TestCharacterListGenerator implements TestListGenerator<Character> {
  @Override
  public SampleElements<Character> samples() {
    return new Chars();
  }

  @Override

 *
 * @author Louis Wasserman
 * @since 15.0
 */
@GwtCompatible
public abstract class ForwardingSortedMultiset<E extends @Nullable Object>
    extends ForwardingMultiset<E> implements SortedMultiset<E> {
  /** Constructor for use by subclasses. */
  protected ForwardingSortedMultiset() {}

  @Override
  protected abstract SortedMultiset<E> delegate();

  @Override
  public NavigableSet<E> elementSet() {

    }

    /**
     * Returns the canonical path string for this abstract pathname.
     *
     * @param file the file (must not be {@literal null})
     * @return the canonical pathname string representing the same file or directory as this abstract pathname
     */
    public static String getCanonicalPath(final File file) {
        assertArgumentNotNull("file", file);

import org.jspecify.annotations.NullMarked;

/**
 * Implementation helper for {@link TestMapGenerator} for use with enum maps.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public abstract class TestEnumMapGenerator implements TestMapGenerator<AnEnum, String> {

  @Override
  public SampleElements<Entry<AnEnum, String>> samples() {
    return new SampleElements<>(
        mapEntry(AnEnum.A, "January"),

 * DiscreteDomain}</a>.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@GwtCompatible
public abstract class DiscreteDomain<C extends Comparable> {

  /**
   * Returns the discrete domain for values of type {@code Integer}.
   *
   * <p>This method always returns the same object. That object is serializable; deserializing it