@Override
    @CheckForNull
    public E floor(@ParametricNullness E e) {
      return delegate.floor(e);
    }

    @Override
    @CheckForNull
    public E ceiling(@ParametricNullness E e) {
      return delegate.ceiling(e);
    }

    @Override
    @CheckForNull
    public E higher(@ParametricNullness E e) {
      return delegate.higher(e);
    }

    @Override

   *
   * <p>The returned iterable's iterator supports {@code remove()} if the iterator of the underlying
   * iterable supports it. Note that it is <i>not</i> possible to delete the last skipped element by
   * immediately calling {@code remove()} on that iterator, as the {@code Iterator} contract states
   * that a call to {@code remove()} before a call to {@code next()} will throw an {@link
   * IllegalStateException}.
   *

   * type {@code K}. Using an {@code EntryTransformer} key type for which this may not hold, such as
   * {@code ArrayList}, may risk a {@code ClassCastException} when calling methods on the
   * transformed multimap.
   *
   * @since 7.0
   */
  public static <
          K extends @Nullable Object, V1 extends @Nullable Object, V2 extends @Nullable Object>

        }
      } else {
        super.add(elements);
      }
      return this;
    }

    private void addDeduping(E element) {
      requireNonNull(hashTable); // safe because we check for null before calling this method
      int mask = hashTable.length - 1;
      int hash = element.hashCode();
      for (int i = Hashing.smear(hash); ; i++) {
        i &= mask;
        Object previous = hashTable[i];

   * {@code k.equals(k2)} implies that {@code k2} is also of type {@code K}. Using a key type for
   * which this may not hold, such as {@code ArrayList}, may risk a {@code ClassCastException} when
   * calling methods on the resulting map view.
   *
   * @since 14.0
   */
  public static <K extends @Nullable Object, V extends @Nullable Object> Map<K, V> asMap(
      Set<K> set, Function<? super K, V> function) {

  }

  /**
   * 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> ImmutableSetMultimap<K, V> of() {
    return (ImmutableSetMultimap<K, V>) EmptyImmutableSetMultimap.INSTANCE;

  @CheckForNull
  public E floor(E e) {
    return Iterators.<@Nullable E>getNext(headSet(e, true).descendingIterator(), null);
  }

  /** @since 12.0 */
  @Override
  @CheckForNull
  public E ceiling(E e) {
    return Iterables.<@Nullable E>getFirst(tailSet(e, true), null);
  }

  /** @since 12.0 */
  @GwtIncompatible // NavigableSet
  @Override
  @CheckForNull
  public E higher(E e) {

   * benchmarking
   * on Open JDK 7, {@link #immutableSortedCopy} generally performs better (in both time and space)
   * than this method, and this method in turn generally performs better than copying the list and
   * calling {@link Collections#sort(List)}.
   */
  // TODO(kevinb): rerun benchmarks including new options
  @SuppressWarnings("nullness") // TODO: b/316358623 - Remove after checker fix.

    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  /**
   * Returns the empty bimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting to any type is safe because the set will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableBiMap<K, V> of() {
    return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
  }

    assertEquals("b", consumingIterator.next());
    assertThat(list).isEmpty();

    assertFalse(consumingIterator.hasNext());
  }

  @GwtIncompatible // ?
  // TODO: Figure out why this is failing in GWT.
  public void testConsumingIterator_duelingIterators() {
    // Test data
    List<String> list = Lists.newArrayList("a", "b");

    // Test & Verify