}

  /**
   * A sensible definition of {@link #lower} in terms of the {@code descendingIterator} method of
   * {@link #headSet(Object, boolean)}. If you override {@link #headSet(Object, boolean)}, you may
   * wish to override {@link #lower} to forward to this implementation.
   */
  @CheckForNull
  protected E standardLower(@ParametricNullness E e) {
    return Iterators.getNext(headSet(e, false).descendingIterator(), null);
  }

   * {@link SortedMultiset#tailMultiset}, the {@code size()} and {@code iterator()} methods of
   * {@link SortedMultiset#entrySet}, and {@link SortedMultiset#remove(Object, int)}. In many
   * situations, you may wish to override {@link SortedMultiset#elementSet} to forward to this
   * implementation or a subclass thereof.
   *
   * @since 15.0
   */
  protected class StandardElementSet extends SortedMultisets.NavigableElementSet<E> {

   * override {@link #equals} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardEquals(@CheckForNull Object object) {
    return Multisets.equalsImpl(this, object);
  }

  /**
   * A sensible definition of {@link #hashCode} as {@code entrySet().hashCode()} . If you override

   * this implementation.
   *
   * @since 7.0
   */
  protected Iterator<E> standardIterator() {
    return listIterator();
  }

  /**
   * A sensible default implementation of {@link #listIterator()}, in terms of {@link
   * #listIterator(int)}. If you override {@link #listIterator(int)}, you may wish to override

    return delegate().tailSet(fromElement);
  }

  /**
   * A sensible definition of {@link #contains} in terms of the {@code first()} method of {@link
   * #tailSet}. If you override {@link #tailSet}, you may wish to override {@link #contains} to
   * forward to this implementation.
   *
   * @since 7.0
   */
  @Override
  protected boolean standardContains(@CheckForNull Object object) {
    try {

   * {@link SortedMultiset#tailMultiset}, the {@code size()} and {@code iterator()} methods of
   * {@link SortedMultiset#entrySet}, and {@link SortedMultiset#remove(Object, int)}. In many
   * situations, you may wish to override {@link SortedMultiset#elementSet} to forward to this
   * implementation or a subclass thereof.
   */
  protected class StandardElementSet extends SortedMultisets.ElementSet<E> {

 * of the {@code Immutable*} types</a> for more information on the properties and guarantees
 * provided by this class.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @author Jens Nyman
 * @param <N> Node parameter type
 * @since 20.0
 */
@Beta
@Immutable(containerOf = {"N"})
@ElementTypesAreNonnullByDefault
public class ImmutableGraph<N> extends ForwardingGraph<N> {

  @Override
  @ParametricNullness
  public E element() {
    return delegate().element();
  }

  /**
   * A sensible definition of {@link #offer} in terms of {@link #add}. If you override {@link #add},
   * you may wish to override {@link #offer} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardOffer(@ParametricNullness E e) {
    try {
      return add(e);

    return delegate().hashCode();
  }

  /**
   * A sensible definition of {@link #equals(Object)} in terms of {@link #getKey()} and {@link
   * #getValue()}. If you override either of these methods, you may wish to override {@link
   * #equals(Object)} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardEquals(@CheckForNull Object object) {
    if (object instanceof Entry) {

    return delegate().tailSet(fromElement);
  }

  /**
   * A sensible definition of {@link #contains} in terms of the {@code first()} method of {@link
   * #tailSet}. If you override {@link #tailSet}, you may wish to override {@link #contains} to
   * forward to this implementation.
   *
   * @since 7.0
   */
  @Override
  protected boolean standardContains(@CheckForNull Object object) {
    try {