* in terms of {@link #invalidate}. The method {@link #cleanUp} is a no-op. All other methods throw
 * an {@link UnsupportedOperationException}.
 *
 * @author Charles Fry
 * @since 11.0
 */
@GwtIncompatible
public abstract class AbstractLoadingCache<K, V> extends AbstractCache<K, V>
    implements LoadingCache<K, V> {

  /** Constructor for use by subclasses. */

 * href="https://www.gwtproject.org/">GWT</a> or <a href="https://github.com/google/j2cl">J2CL</a>.
 *
 * <p>Note that a {@code GwtCompatible} type may have some {@link GwtIncompatible} methods.
 *
 * @author Charles Fry
 * @author Hayward Chan
 */
@Retention(RetentionPolicy.CLASS)
@Target({ElementType.TYPE, ElementType.METHOD})
@Documented
@GwtCompatible
public @interface GwtCompatible {

  /**

 * <p>This annotation behaves identically to <a href=
 * "http://www.gwtproject.org/javadoc/latest/com/google/gwt/core/shared/GwtIncompatible.html">the
 * {@code @GwtIncompatible} annotation in GWT itself</a>.
 *
 * @author Charles Fry
 */
@Retention(RetentionPolicy.CLASS)
@Target({ElementType.TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.FIELD})
@Documented
@GwtCompatible
public @interface GwtIncompatible {
  /**

 *
 * <p>Like other {@code Entry} instances associated with {@code CacheBuilder}, this class holds
 * strong references to the key and value, regardless of the type of references the cache may be
 * using.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public final class RemovalNotification<K, V>
    extends SimpleImmutableEntry<@Nullable K, @Nullable V> {
  private final RemovalCause cause;

  /**

 * their default implementations. When those implementations invoke methods, they invoke methods on
 * the {@code ForwardingConcurrentMap}.
 *
 * @author Charles Fry
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingConcurrentMap<K, V> extends ForwardingMap<K, V>
    implements ConcurrentMap<K, V> {

  /** Constructor for use by subclasses. */

import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentMap;

/**
 * The reason why a cached entry was removed.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public enum RemovalCause {
  /**
   * The entry was manually removed by the user. This can result from the user invoking {@link

 *     if any key is acceptable
 * @param <V> the most general type of values this listener can listen for; for example {@code
 *     Object} if any key is acceptable
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
@FunctionalInterface
public interface RemovalListener<K, V> {
  /**
   * Notifies the listener that a removal occurred at some point in the past.
   *

 *     if any key is acceptable
 * @param <V> the most general type of values this listener can listen for; for example {@code
 *     Object} if any key is acceptable
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public interface RemovalListener<K, V> {
  /**
   * Notifies the listener that a removal occurred at some point in the past.
   *

 * their default implementations. When those implementations invoke methods, they invoke methods on
 * the {@code ForwardingConcurrentMap}.
 *
 * @author Charles Fry
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingConcurrentMap<K, V> extends ForwardingMap<K, V>
    implements ConcurrentMap<K, V> {

  /** Constructor for use by subclasses. */

import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentMap;

/**
 * The reason why a cached entry was removed.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public enum RemovalCause {
  /**
   * The entry was manually removed by the user. This can result from the user invoking {@link