@Override
    public boolean removeAll(Collection<?> elementsToRemove) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean retainAll(Collection<?> elementsToRetain) {
      throw new UnsupportedOperationException();
    }

    @Override
    public void clear() {
      throw new UnsupportedOperationException();
    }

    @Override

   * implement {@link Comparable}.
   */
  public static <E extends Comparable<?>> Builder<E> naturalOrder() {
    return new Builder<>(Ordering.natural());
  }

  /**
   * A builder for creating immutable sorted set instances, especially {@code public static final}
   * sets ("constant sets"), with a given comparator. Example:
   *
   * <pre>{@code
   * public static final ImmutableSortedSet<Number> LUCKY_NUMBERS =

  public K ceilingKey(K key) {
    return keyOrNull(ceilingEntry(key));
  }

  @Override
  @CheckForNull
  public Entry<K, V> higherEntry(K key) {
    return tailMap(key, false).firstEntry();
  }

  @Override
  @CheckForNull
  public K higherKey(K key) {
    return keyOrNull(higherEntry(key));
  }

  @Override
  @CheckForNull
  public Entry<K, V> firstEntry() {

   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableSetMultimap<K, V> of() {
    return (ImmutableSetMultimap<K, V>) EmptyImmutableSetMultimap.INSTANCE;
  }

  /** Returns an immutable multimap containing a single entry. */
  public static <K, V> ImmutableSetMultimap<K, V> of(K k1, V v1) {

    }

    @Override
    public Iterator<T> iterator() {
      return Iterators.unmodifiableIterator(iterable.iterator());
    }

    @Override
    public String toString() {
      return iterable.toString();
    }
    // no equals and hashCode; it would break the contract!
  }

  /** Returns the number of elements in {@code iterable}. */
  public static int size(Iterable<?> iterable) {

/**
 * Tester for {@code Spliterator} implementations.
 *
 * @since 21.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class SpliteratorTester<E extends @Nullable Object> {
  /** Return type from "contains the following elements" assertions. */
  public interface Ordered {
    /**
     * Attests that the expected values must not just be present but must be present in the order
     * they were given.

 * intended to "fill the gap" and provide those features of {@code Ordering} not already provided by
 * the JDK.
 *
 * @since 21.0
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Comparators {
  private Comparators() {}

  /**
   * Returns a new comparator which sorts iterables by comparing corresponding elements pairwise

  public final void clear() {
    throw new UnsupportedOperationException();
  }

  @Override
  public boolean isEmpty() {
    return size() == 0;
  }

  @Override
  public boolean containsKey(@CheckForNull Object key) {
    return get(key) != null;
  }

  @Override
  public boolean containsValue(@CheckForNull Object value) {
    return values().contains(value);
  }

    };
  }

  @Override
  public int hashCode() {
    return asMapOfRanges().hashCode();
  }

  @Override
  public boolean equals(@CheckForNull Object o) {
    if (o instanceof RangeMap) {
      RangeMap<?, ?> rangeMap = (RangeMap<?, ?>) o;
      return asMapOfRanges().equals(rangeMap.asMapOfRanges());
    }
    return false;
  }

  @Override
  public String toString() {

  public void removeAll(Iterable<Range<C>> other) {
    throw new UnsupportedOperationException();
  }

  @Override
  public ImmutableSet<Range<C>> asRanges() {
    if (ranges.isEmpty()) {
      return ImmutableSet.of();
    }
    return new RegularImmutableSortedSet<>(ranges, Range.<C>rangeLexOrdering());
  }

  @Override
  public ImmutableSet<Range<C>> asDescendingSetOfRanges() {