@Override
  @CheckForNull
  public Entry<K, V> lowerEntry(@ParametricNullness K key) {
    return delegate().lowerEntry(key);
  }

  /**
   * A sensible definition of {@link #lowerEntry} in terms of the {@code lastEntry()} of {@link
   * #headMap(Object, boolean)}. If you override {@code headMap}, you may wish to override {@code
   * lowerEntry} to forward to this implementation.
   */
  @CheckForNull

  @Override
  @CheckForNull
  public Entry<K, V> lowerEntry(@ParametricNullness K key) {
    return delegate().lowerEntry(key);
  }

  /**
   * A sensible definition of {@link #lowerEntry} in terms of the {@code lastEntry()} of {@link
   * #headMap(Object, boolean)}. If you override {@code headMap}, you may wish to override {@code
   * lowerEntry} to forward to this implementation.
   */
  @CheckForNull

   * A sensible definition of {@link #clear} in terms of the {@code iterator} method of {@link
   * #entrySet}. In many cases, you may wish to override {@link #clear} to forward to this
   * implementation.
   *
   * @since 7.0
   */
  protected void standardClear() {
    Iterators.clear(entrySet().iterator());
  }

  /**
   * A sensible implementation of {@link Map#keySet} in terms of the following methods: {@link

/**
 * Static methods pertaining to sorted {@link List} instances.
 *
 * <p>In this documentation, the terms <i>greatest</i>, <i>greater</i>, <i>least</i>, and
 * <i>lesser</i> are considered to refer to the comparator on the elements, and the terms
 * <i>first</i> and <i>last</i> are considered to refer to the elements' ordering in a list.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

 * Law</a>).
 *
 * <p>A {@code RateLimiter} is defined primarily by the rate at which permits are issued. Absent
 * additional configuration, permits will be distributed at a fixed rate, defined in terms of
 * permits per second. Permits will be distributed smoothly, with the delay between individual
 * permits being adjusted to ensure that the configured rate is maintained.
 *

@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class ConcurrentHashMultiset<E> extends AbstractMultiset<E> implements Serializable {

  /*
   * The ConcurrentHashMultiset's atomic operations are implemented primarily in terms of
   * AtomicInteger's atomic operations, with some help from ConcurrentMap's atomic operations on
   * creation and removal (including automatic removal of zeroes). If the modification of an

 * {@link Comparable} class specification. Otherwise, the resulting multiset will violate the {@link
 * java.util.Collection} contract, which is specified in terms of {@link Object#equals}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multiset">{@code Multiset}</a>.
 *
 * @author Louis Wasserman

        queue[index] = parentElement;
        queue[parentIndex] = x;
        return parentIndex;
      }
      queue[index] = x;
      return index;
    }

    // About the term "aunt node": it's better to leave gender out of it, but for this the English
    // language has nothing for us. Except for the whimsical neologism "pibling" (!) which we

   * {@link ListenableFutureTask} instances to the given delegate executor. Those methods, as well
   * as {@code execute} and {@code invokeAny}, are implemented in terms of calls to {@code
   * delegate.execute}. All other methods are forwarded unchanged to the delegate. This implies that
   * the returned {@code ListeningExecutorService} never calls the delegate's {@code submit}, {@code

 *
 * <h3>Capabilities</h3>
 *
 * <p>{@code ValueGraph} supports the following use cases (<a
 * href="https://github.com/google/guava/wiki/GraphsExplained#definitions">definitions of
 * terms</a>):
 *
 * <ul>
 *   <li>directed graphs
 *   <li>undirected graphs
 *   <li>graphs that do/don't allow self-loops
 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered