}
  }

  /**
   * A sensible definition of {@link #peek} in terms of {@link #element}. If you override {@link
   * #element}, you may wish to override {@link #peek} to forward to this implementation.
   *
   * @since 7.0
   */
  protected @Nullable E standardPeek() {
    try {
      return element();
    } catch (NoSuchElementException caught) {
      return null;
    }
  }

  /**

    // Add more than two elements to increment size removals.
    cache.put(3, 20);
    cache.put(6, 2);
    cache.put(98, 45);
    cache.put(56, 76);
    cache.put(23, 84);

    // Replace the two present elements.
    cache.put(23, 20);
    cache.put(56, 49);
    cache.put(23, 2);
    cache.put(56, 4);

    // Expire the two present elements.
    fakeTicker.advance(1001, MILLISECONDS);

 *
 * @author Louis Wasserman
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum MultisetFeature implements Feature<Multiset> {
  /**
   * Indicates that elements from {@code Multiset.entrySet()} update to reflect changes in the
   * backing multiset.
   */
  ENTRIES_ARE_VIEWS;

  @Override
  public Set<Feature<? super Multiset>> getImpliedFeatures() {
    return emptySet();

public class CollectionSerializationTester<E> extends AbstractCollectionTester<E> {
  @CollectionFeature.Require(SERIALIZABLE)
  public void testReserialize() {
    // For a bare Collection, the most we can guarantee is that the elements are preserved.
    assertEqualIgnoringOrder(actualContents(), SerializableTester.reserialize(actualContents()));
  }

 */
package org.codelibs.core.collection;

import java.util.Enumeration;

/**
 * An empty {@link Enumeration}.
 *
 * @author higa
 * @param <T> the type of elements
 */
public class EmptyEnumeration<T> extends IteratorEnumeration<T> {

    /**
     * Creates an {@link EmptyEnumeration}.
     */
    public EmptyEnumeration() {
        super(new EmptyIterator<T>());
    }

    @Override
    public boolean addAll(int index, Collection<? extends V> elements) {
      checkNotNull(elements);
      checkPositionIndex(index, 0);
      throw new IllegalArgumentException("Key does not satisfy predicate: " + key);
    }

    @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types
    @Override
    protected List<V> delegate() {
      return emptyList();
    }

    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public List<E> create(Object... elements) {
      return (List<E>) SerializableTester.reserialize(gen.create(elements));
    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override

    @Override
    public boolean addAll(int index, Collection<? extends V> elements) {
      checkNotNull(elements);
      checkPositionIndex(index, 0);
      throw new IllegalArgumentException("Key does not satisfy predicate: " + key);
    }

    @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types
    @Override
    protected List<V> delegate() {
      return emptyList();
    }

     *
     * @param converter
     *            The converter. Must not be {@literal null}.
     * @param propertyNames
     *            The property names to which this converter will be applied. Each element must not be {@literal null} or an empty string.
     * @return A {@link CopyOptions} with the specified converter applied.
     * @see CopyOptions#converter(Converter, CharSequence...)
     */

public abstract class ImmutableMap<K, V> implements Map<K, V>, Serializable {

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements.
   * Entries appear in the result {@code ImmutableMap} in encounter order.
   *