* multiple sets in series. Each set is a superset of the set created before it.
   *
   * @since 2.0
   */
  public static final class Builder<E> extends ImmutableSet.Builder<E> {
    private final Comparator<? super E> comparator;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableSortedSet#orderedBy}.

   * build multiple maps in series. Each map is a superset of the maps created before it.
   *
   * @since 2.0
   */
  public static class Builder<K, V> extends ImmutableMap.Builder<K, V> {
    private transient @Nullable Object[] keys;
    private transient @Nullable Object[] values;
    private final Comparator<? super K> comparator;

    /**

   * multiple multimaps in series. Each multimap contains the key-value mappings in the previously
   * created multimaps.
   *
   * @since 2.0
   */
  public static final class Builder<K, V> extends ImmutableMultimap.Builder<K, V> {
    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableSetMultimap#builder}.
     */

 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Multisets {
  private Multisets() {}

  /**
   * Returns a {@code Collector} that accumulates elements into a multiset created via the specified
   * {@code Supplier}, whose elements are the result of applying {@code elementFunction} to the
   * inputs, with counts equal to the result of applying {@code countFunction} to the inputs.

      }
      entriesUsed = true;
      ImmutableMap<K, V> map =
          RegularImmutableMap.create(localSize, localAlternatingKeysAndValues, this);
      if (throwIfDuplicateKeys && duplicateKey != null) {
        throw duplicateKey.exception();
      }
      return map;
    }

    /**
     * Returns a newly-created immutable map. The iteration order of the returned map is the order

   *
   * <p>This is essentially the same as {@code
   * TreeRangeSet.create(this).removeAll(other.complement())} except it returns an {@code
   * ImmutableRangeSet}.
   *
   * @since 21.0
   */
  public ImmutableRangeSet<C> intersection(RangeSet<C> other) {
    RangeSet<C> copy = TreeRangeSet.create(this);
    copy.removeAll(other.complement());
    return copyOf(copy);
  }

  /**

  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);
    return Range.create(firstRange.lowerBound, lastRange.upperBound);
  }

  /**
   * Guaranteed to throw an exception and leave the {@code RangeMap} unmodified.
   *
   * @throws UnsupportedOperationException always

   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,
   * use the {@code HashSet} constructor directly, taking advantage of <a
   * href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
   */
  public static <E extends @Nullable Object> HashSet<E> newHashSet() {
    return new HashSet<>();
  }

  /**
   * Creates a <i>mutable</i> {@code HashSet} instance initially containing the given elements.

   *
   * @since 11.0
   */
  @DoNotMock
  public static final class Builder<R, C, V> {
    private final List<Cell<R, C, V>> cells = Lists.newArrayList();
    @CheckForNull private Comparator<? super R> rowComparator;
    @CheckForNull private Comparator<? super C> columnComparator;

    /**

   * build multiple bimaps in series. Each bimap is a superset of the bimaps created before it.
   *
   * @since 2.0
   */
  public static final class Builder<K, V> extends ImmutableMap.Builder<K, V> {
    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableBiMap#builder}.
     */