*/

    @Override
    public @Nullable Entry<K, V> pollFirstEntry() {
      return standardPollFirstEntry();
    }

    @Override
    public @Nullable Entry<K, V> pollLastEntry() {
      return standardPollLastEntry();
    }

    @Override
    public NavigableMap<K, V> descendingMap() {
      return new StandardDescendingMap();
    }

    @Override

     */

    @Override
    public @Nullable Entry<K, V> pollFirstEntry() {
      return standardPollFirstEntry();
    }

    @Override
    public @Nullable Entry<K, V> pollLastEntry() {
      return standardPollLastEntry();
    }

    @Override
    public NavigableMap<K, V> descendingMap() {
      return new StandardDescendingMap();
    }

    @Override

   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final @Nullable Entry<E> pollLastEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  public abstract ImmutableSortedMultiset<E> headMultiset(E upperBound, BoundType boundType);

  @Override

    @Override
    public @Nullable Entry<K, Collection<V>> pollFirstEntry() {
      return pollAsMapEntry(entrySet().iterator());
    }

    @Override
    public @Nullable Entry<K, Collection<V>> pollLastEntry() {
      return pollAsMapEntry(descendingMap().entrySet().iterator());
    }

    @Nullable Entry<K, Collection<V>> pollAsMapEntry(
        Iterator<Entry<K, Collection<V>>> entryIterator) {