* {@link SortedMultiset#tailMultiset}, the {@code size()} and {@code iterator()} methods of
   * {@link SortedMultiset#entrySet}, and {@link SortedMultiset#remove(Object, int)}. In many
   * situations, you may wish to override {@link SortedMultiset#elementSet} to forward to this
   * implementation or a subclass thereof.
   */

    } else { // successor
      adjacentNodeValues.remove(node);
      removedValue = previousValue;
    }

    if (removedValue != null) {
      checkNonNegative(--successorCount);

      if (orderedNodeConnections != null) {
        orderedNodeConnections.remove(new NodeConnection.Succ<>((N) node));
      }
    }

    /*

 * the ICUNormalizer instance.</p>
 *
 * <p>Example usage:</p>
 * <pre>
 * ICUNormalizer normalizer = new ICUNormalizer("Any-Latin; NFD; [:Nonspacing Mark:] Remove; NFC");
 * String normalizedText = normalizer.normalize("text to normalize", "field");
 * </pre>
 *
 * @see com.ibm.icu.text.Transliterator
 */
public class ICUNormalizer implements Normalizer {

    if (entryIterator.hasNext()) {
      Entry<E> result = entryIterator.next();
      result = Multisets.immutableEntry(result.getElement(), result.getCount());
      entryIterator.remove();
      return result;
    }
    return null;
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {
    Iterator<Entry<E>> entryIterator = descendingEntryIterator();

    }
  }

  /**
   * Precondition tester for {@code Iterator.remove()} that throws an exception with a consistent
   * error message.
   */
  static void checkRemove(boolean canRemove) {
    checkState(canRemove, "no calls to next() since the last call to remove()");
  }

  private CollectPreconditions() {}

    Set<Feature<?>> inverseFeatures = new HashSet<>(mapFeatures);

    boolean nullKeys = inverseFeatures.remove(MapFeature.ALLOWS_NULL_KEYS);
    boolean nullValues = inverseFeatures.remove(MapFeature.ALLOWS_NULL_VALUES);

    if (nullKeys) {
      inverseFeatures.add(MapFeature.ALLOWS_NULL_VALUES);
    }
    if (nullValues) {

    assertTrue(result.remove(v0()));
    assertFalse(multimap().containsEntry(k0(), v0()));
    assertEquals(2, multimap().size());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testPropagatesRemoveLastElementToMultimap() {
    Collection<V> result = multimap().get(k0());
    assertTrue(result.remove(v0()));
    assertGet(k0());
  }

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemove() {
    assertContentsInOrder(multimap().asMap().remove(k0()), v0());
    assertGet(k0());
    assertEquals(getNumElements() - 1, multimap().size());
  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_PUT)

    map.put("quux", 3);

    map.remove("bar");
    assertThat(map.entrySet())
        .containsExactly(immutableEntry("foo", 1), immutableEntry("quux", 3))
        .inOrder();
  }

  public void testInsertionOrderAfterRemoveLast() {
    BiMap<String, Integer> map = HashBiMap.create();
    map.put("foo", 1);
    map.put("bar", 2);
    map.put("quux", 3);

    map.remove("quux");
    assertThat(map.entrySet())

 *
 * <p>This enum is GWT compatible.
 *
 * @author Chris Povirk
 */
@GwtCompatible
public enum IteratorFeature {
  /** Support for {@link Iterator#remove()}. */
  SUPPORTS_REMOVE,
  /**
   * Support for {@link ListIterator#add(Object)}; ignored for plain {@link Iterator}
   * implementations.
   */
  SUPPORTS_ADD,
  /**