return new ImmutableSortedMap<>(
          ImmutableSortedSet.emptySet(comparator), ImmutableList.<V>of());
    }
  }

  /**
   * Returns the empty sorted map.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")
  // unsafe, comparator() returns a comparator on the specified type

   *
   * <p>If the mapped elements contain duplicates (according to {@link Object#equals}), the element
   * will be added more than once, with the count summed over all appearances of the element.
   *
   * <p>Note that {@code stream.collect(toMultiset(function, e -> 1, supplier))} is equivalent to
   * {@code stream.map(function).collect(Collectors.toCollection(supplier))}.
   *
   * <p>To collect to an {@link ImmutableMultiset}, use {@link

      Collector<Range<E>, ?, ImmutableRangeSet<E>> toImmutableRangeSet() {
    return CollectCollectors.toImmutableRangeSet();
  }

  /**
   * Returns an empty immutable range set.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")
  public static <C extends Comparable> ImmutableRangeSet<C> of() {
    return (ImmutableRangeSet<C>) EMPTY;
  }

  /**

          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableRangeMap(keyFunction, valueFunction);
  }

  /**
   * Returns an empty immutable range map.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")
  public static <K extends Comparable<?>, V> ImmutableRangeMap<K, V> of() {
    return (ImmutableRangeMap<K, V>) EMPTY;
  }

  /**
   * Returns the empty map. This map behaves and performs comparably to {@link
   * Collections#emptyMap}, and is preferable mainly for consistency and maintainability of your
   * code.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableMap<K, V> of() {
    return (ImmutableMap<K, V>) RegularImmutableMap.EMPTY;
  }

  /**

  }

  /**
   * Creates a <i>mutable</i>, empty {@code HashMap} instance.
   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableMap#of()} instead.
   *
   * <p><b>Note:</b> if {@code K} is an {@code enum} type, use {@link #newEnumMap} instead.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,

  }

  /**
   * Returns the empty immutable set. Preferred over {@link Collections#emptySet} for code
   * consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings({"unchecked"}) // fully variant implementation (never actually produces any Es)
  public static <E> ImmutableSet<E> of() {

   * Returns the empty immutable list. This list behaves and performs comparably to {@link
   * Collections#emptyList}, and is preferable mainly for consistency and maintainability of your
   * code.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting to any type is safe because the list will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <E> ImmutableList<E> of() {

    return CollectCollectors.flatteningToImmutableListMultimap(keyFunction, valuesFunction);
  }

  /**
   * Returns the empty multimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableListMultimap<K, V> of() {

          ToIntFunction<? super T> countFunction) {
    return CollectCollectors.toImmutableMultiset(elementFunction, countFunction);
  }

  /**
   * Returns the empty immutable multiset.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked") // all supported methods are covariant
  public static <E> ImmutableMultiset<E> of() {