@ElementTypesAreNonnullByDefault
final class RegularImmutableSortedSet<E> extends ImmutableSortedSet<E> {
  static final RegularImmutableSortedSet<Comparable> NATURAL_EMPTY_SET =
      new RegularImmutableSortedSet<>(ImmutableList.<Comparable>of(), Ordering.natural());

  @VisibleForTesting final transient ImmutableList<E> elements;

  RegularImmutableSortedSet(ImmutableList<E> elements, Comparator<? super E> comparator) {

import java.util.Comparator;
import java.util.SortedSet;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * GWT emulation of {@link RegularImmutableSortedSet}.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
final class RegularImmutableSortedSet<E> extends ImmutableSortedSet<E> {

  /** true if this set is a subset of another immutable sorted set. */
  final boolean isSubset;

  static final ImmutableSortedMultiset<?> NATURAL_EMPTY_MULTISET =
      new RegularImmutableSortedMultiset<>(Ordering.natural());

  @VisibleForTesting final transient RegularImmutableSortedSet<E> elementSet;
  private final transient long[] cumulativeCounts;
  private final transient int offset;
  private final transient int length;

  RegularImmutableSortedMultiset(Comparator<? super E> comparator) {

  }

  static <E> RegularImmutableSortedSet<E> emptySet(Comparator<? super E> comparator) {
    if (Ordering.natural().equals(comparator)) {
      @SuppressWarnings("unchecked") // The natural-ordered empty set supports all types.
      RegularImmutableSortedSet<E> result =
          (RegularImmutableSortedSet<E>) RegularImmutableSortedSet.NATURAL_EMPTY_SET;
      return result;
    } else {

      new RegularImmutableSortedSet<Object>(
          new TreeSet<Object>((Comparator<Object>) NATURAL_ORDER), false);

  static <E> ImmutableSortedSet<E> emptySet(Comparator<? super E> comparator) {
    checkNotNull(comparator);
    if (NATURAL_ORDER.equals(comparator)) {
      return of();
    } else {
      return new RegularImmutableSortedSet<E>(new TreeSet<E>(comparator), false);
    }
  }

  }

  /** Returns an immutable sorted multiset containing a single element. */
  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E element) {
    RegularImmutableSortedSet<E> elementSet =
        (RegularImmutableSortedSet<E>) ImmutableSortedSet.of(element);
    long[] cumulativeCounts = {0, 1};
    return new RegularImmutableSortedMultiset<>(elementSet, cumulativeCounts, 0, 1);
  }

  /**

  }

  @Override
  public ImmutableMap<Range<K>, V> asMapOfRanges() {
    if (ranges.isEmpty()) {
      return ImmutableMap.of();
    }
    RegularImmutableSortedSet<Range<K>> rangeSet =
        new RegularImmutableSortedSet<>(ranges, Range.<K>rangeLexOrdering());
    return new ImmutableSortedMap<>(rangeSet, values);
  }

  @Override
  public ImmutableMap<Range<K>, V> asDescendingMapOfRanges() {

  }

  @Override
  public ImmutableMap<Range<K>, V> asMapOfRanges() {
    if (ranges.isEmpty()) {
      return ImmutableMap.of();
    }
    RegularImmutableSortedSet<Range<K>> rangeSet =
        new RegularImmutableSortedSet<>(ranges, Range.<K>rangeLexOrdering());
    return new ImmutableSortedMap<>(rangeSet, values);
  }

  @Override
  public ImmutableMap<Range<K>, V> asDescendingMapOfRanges() {

  }

  static <E> RegularImmutableSortedSet<E> emptySet(Comparator<? super E> comparator) {
    if (Ordering.natural().equals(comparator)) {
      @SuppressWarnings("unchecked") // The natural-ordered empty set supports all types.
      RegularImmutableSortedSet<E> result =
          (RegularImmutableSortedSet<E>) RegularImmutableSortedSet.NATURAL_EMPTY_SET;
      return result;
    } else {

   */
  @Override
  ImmutableList<E> subListUnchecked(int fromIndex, int toIndex) {
    ImmutableList<E> parentSubList = super.subListUnchecked(fromIndex, toIndex);
    return new RegularImmutableSortedSet<E>(parentSubList, comparator()).asList();
  }

  @Override
  public Spliterator<E> spliterator() {
    return CollectSpliterators.indexed(
        size(),