Comparator<Object> unsafeComparator() {
    return (Comparator<Object>) comparator;
  }

  RegularImmutableSortedSet<E> getSubSet(int newFromIndex, int newToIndex) {
    if (newFromIndex == 0 && newToIndex == size()) {
      return this;
    } else if (newFromIndex < newToIndex) {
      return new RegularImmutableSortedSet<>(
          elements.subList(newFromIndex, newToIndex), comparator);
    } else {

  }

  @CollectionSize.Require(absent = ZERO)
  public void testOrderedByComparator() {
    Comparator<? super K> comparator = navigableMap.comparator();
    if (comparator == null) {
      comparator =
          new Comparator<K>() {
            @SuppressWarnings("unchecked")
            @Override
            public int compare(K o1, K o2) {

      return toString;
    }
  }

  /**
   * Returns a {@code Comparator<Boolean>} that sorts {@code true} before {@code false}.
   *
   * <p>This is particularly useful in Java 8+ in combination with {@code Comparator.comparing},
   * e.g. {@code Comparator.comparing(Foo::hasBar, trueFirst())}.
   *
   * @since 21.0
   */
  public static Comparator<Boolean> trueFirst() {
    return BooleanComparator.TRUE_FIRST;
  }

  /**

      return toString;
    }
  }

  /**
   * Returns a {@code Comparator<Boolean>} that sorts {@code true} before {@code false}.
   *
   * <p>This is particularly useful in Java 8+ in combination with {@code Comparator.comparing},
   * e.g. {@code Comparator.comparing(Foo::hasBar, trueFirst())}.
   *
   * @since 21.0
   */
  public static Comparator<Boolean> trueFirst() {
    return BooleanComparator.TRUE_FIRST;
  }

  /**

    // The Unsafe implementation if it's available. Otherwise, the Java implementation.
    Comparator<byte[]> comparator = UnsignedBytes.lexicographicalComparator();
    Helpers.testComparator(comparator, ordered);
    assertThat(SerializableTester.reserialize(comparator)).isSameInstanceAs(comparator);

    // The Java implementation.
    Comparator<byte[]> javaImpl = UnsignedBytes.lexicographicalComparatorJavaImpl();

          Comparator<? super E> comparator = spliterator.getComparator();
          if (comparator == null) {
            // A sorted spliterator with no comparator is already using natural order.
            // (We could probably find a way to avoid rawtypes here if we wanted.)
            @SuppressWarnings({"unchecked", "rawtypes"})
            Comparator<? super E> naturalOrder =

          Comparator<? super E> comparator = spliterator.getComparator();
          if (comparator == null) {
            // A sorted spliterator with no comparator is already using natural order.
            // (We could probably find a way to avoid rawtypes here if we wanted.)
            @SuppressWarnings({"unchecked", "rawtypes"})
            Comparator<? super E> naturalOrder =

      return notSubtype(shop);
    }

    @TestSubtype(suppressGetSubtype = true)
    public Comparator<Electronics> supertypeIsTopLevelClass(
        Mall<Indoor>.Retailer<Electronics> shop) {
      return isSubtype(shop);
    }

    @TestSubtype
    public Comparator<Electronics> topLevelClassIsNotSupertypeDueToTypeParameter(
        Mall<Indoor>.Retailer<Grocery> shop) {

    return (Collector) TO_IMMUTABLE_SET;
  }

  static <E> Collector<E, ?, ImmutableSortedSet<E>> toImmutableSortedSet(
      Comparator<? super E> comparator) {
    checkNotNull(comparator);
    return Collector.of(
        () -> new ImmutableSortedSet.Builder<E>(comparator),
        ImmutableSortedSet.Builder::add,
        ImmutableSortedSet.Builder::combine,
        ImmutableSortedSet.Builder::build);
  }

     */
    private static final int UNSET_EXPECTED_SIZE = -1;

    private final Comparator<B> comparator;
    private int expectedSize = UNSET_EXPECTED_SIZE;
    private int maximumSize = Integer.MAX_VALUE;

    private Builder(Comparator<B> comparator) {
      this.comparator = checkNotNull(comparator);
    }

    /**