result.descendingSet = this;
    }
    return result;
  }

  // Most classes should implement this as new DescendingImmutableSortedSet<E>(this),
  // but we push down that implementation because ProGuard can't eliminate it even when it's always
  // overridden.
  @GwtIncompatible // NavigableSet
  abstract ImmutableSortedSet<E> createDescendingSet();

  /** @since 12.0 */

   * @since 11.0
   */
  public static <E extends @Nullable Object> SortedMultiset<E> unmodifiableSortedMultiset(
      SortedMultiset<E> sortedMultiset) {
    // it's in its own file so it can be emulated for GWT
    return new UnmodifiableSortedMultiset<>(checkNotNull(sortedMultiset));
  }

  /**
   * Returns an immutable multiset entry with the specified element and count. The entry will be

     * contrast to the "V?" type that we're using. As a result, Kotlin sees a conflict between the
     * nullness annotations in ImmutableMap and those in its own Map type. In response, it considers
     * the parameter and return type both to be platform types. As a result, Kotlin permits calls
     * that can lead to NullPointerException. That's unfortunate. But hopefully most Kotlin callers

    Preconditions.checkNotNull(valueEquivalence);

    Map<K, V> onlyOnLeft = newLinkedHashMap();
    Map<K, V> onlyOnRight = new LinkedHashMap<>(right); // will whittle it down
    Map<K, V> onBoth = newLinkedHashMap();
    Map<K, MapDifference.ValueDifference<V>> differences = newLinkedHashMap();
    doDifference(left, right, valueEquivalence, onlyOnLeft, onlyOnRight, onBoth, differences);

    subject to change. They can be modified in any way, or even removed, at any
    time. If your code is a library itself (i.e., it is used on the CLASSPATH of
    users outside your own control), you should not use beta APIs unless you
    [repackage] them. **If your code is a library, we strongly recommend using
    the [Guava Beta Checker] to ensure that you do not use any `@Beta` APIs!**

   *
   * @since 2.0
   */
  public abstract static class SetView<E extends @Nullable Object> extends AbstractSet<E> {
    private SetView() {} // no subclasses but our own

    /**
     * Returns an immutable copy of the current contents of this set view. Does not support null
     * elements.
     *

   * the map are reflected in the multimap, and vice versa. If the map is modified while an
   * iteration over one of the multimap's collection views is in progress (except through the
   * iterator's own {@code remove} operation, or through the {@code setValue} operation on a map
   * entry returned by the iterator), the results of the iteration are undefined.
   *

    @VisibleForTesting E[] elements;
    private int[] counts;

    /*
     * The number of used positions in the elements array.  We deduplicate periodically, so this
     * may fluctuate up and down.
     */
    private int length;

    // True if we just called build() and the elements array is being used by a created ISM, meaning
    // we shouldn't modify that array further.

   * String a3 = peekingIterator.next(); // also returns "a"
   * }</pre>
   *
   * <p>Any structural changes to the underlying iteration (aside from those performed by the
   * iterator's own {@link PeekingIterator#remove()} method) will leave the iterator in an undefined
   * state.
   *
   * <p>The returned iterator does not support removal after peeking, as explained by {@link
   * PeekingIterator#remove()}.