return intersectionInCurrentDomain(Range.upTo(toElement, BoundType.forBoolean(inclusive)));
  }

  @Override
  @SuppressWarnings("unchecked") // TODO(cpovirk): Use a shared unsafeCompare method.
  ContiguousSet<C> subSetImpl(
      C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
    if (fromElement.compareTo(toElement) == 0 && !fromInclusive && !toInclusive) {

    if (!thisIterator.hasNext()) {
      return false;
    }

    Object target = thatIterator.next();
    E current = thisIterator.next();
    try {
      while (true) {
        int cmp = unsafeCompare(current, target);

        if (cmp < 0) {
          if (!thisIterator.hasNext()) {
            return false;
          }
          current = thisIterator.next();
        } else if (cmp == 0) {

    return intersectionInCurrentDomain(Range.upTo(toElement, BoundType.forBoolean(inclusive)));
  }

  @Override
  @SuppressWarnings("unchecked") // TODO(cpovirk): Use a shared unsafeCompare method.
  ContiguousSet<C> subSetImpl(
      C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
    if (fromElement.compareTo(toElement) == 0 && !fromInclusive && !toInclusive) {

    if (!thisIterator.hasNext()) {
      return false;
    }

    Object target = thatIterator.next();
    E current = thisIterator.next();
    try {
      while (true) {
        int cmp = unsafeCompare(current, target);

        if (cmp < 0) {
          if (!thisIterator.hasNext()) {
            return false;
          }
          current = thisIterator.next();
        } else if (cmp == 0) {

        forceCopy = true;
        return new RegularImmutableSortedSet<>(asImmutableList(elements, n), comparator);
      }
    }
  }

  int unsafeCompare(Object a, @Nullable Object b) {
    return unsafeCompare(comparator, a, b);
  }

  static int unsafeCompare(Comparator<?> comparator, Object a, @Nullable Object b) {
    // Pretend the comparator can compare anything. If it turns out it can't

      this.forceCopy = true;
      return result;
    }
  }

  int unsafeCompare(Object a, @Nullable Object b) {
    return unsafeCompare(comparator, a, b);
  }

  static int unsafeCompare(Comparator<?> comparator, Object a, @Nullable Object b) {
    // Pretend the comparator can compare anything. If it turns out it can't