assertNull(forwarding.lastEntry());
    forwarding.put("b", 2);
    assertEquals(immutableEntry("b", 2), forwarding.lastEntry());
    forwarding.put("c", 3);
    assertEquals(immutableEntry("c", 3), forwarding.lastEntry());
    forwarding.put("a", 1);
    assertEquals(immutableEntry("c", 3), forwarding.lastEntry());
    forwarding.remove("c");

    return Multisets.immutableEntry(entry.getElement(), entry.getCount());
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  /**
   * A sensible definition of {@link #lastEntry()} in terms of {@code
   * descendingMultiset().entrySet().iterator()}.
   *

    assertNull(forwarding.lastEntry());
    forwarding.put("b", 2);
    assertEquals(immutableEntry("b", 2), forwarding.lastEntry());
    forwarding.put("c", 3);
    assertEquals(immutableEntry("c", 3), forwarding.lastEntry());
    forwarding.put("a", 1);
    assertEquals(immutableEntry("c", 3), forwarding.lastEntry());
    forwarding.remove("c");

  public @Nullable Entry<E> firstEntry() {
    Iterator<Entry<E>> entryIterator = entryIterator();
    return entryIterator.hasNext() ? entryIterator.next() : null;
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    Iterator<Entry<E>> entryIterator = descendingEntryIterator();
    return entryIterator.hasNext() ? entryIterator.next() : null;
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {

  private transient int lastEntry;

  CompactLinkedHashSet() {}

  CompactLinkedHashSet(int expectedSize) {
    super(expectedSize);
  }

  @Override
  void init(int expectedSize) {
    super.init(expectedSize);
    this.firstEntry = ENDPOINT;
    this.lastEntry = ENDPOINT;
  }

  @Override
  int allocArrays() {

      setSuccessor(pred, succ);
    }
    if (succ == ENDPOINT) {
      lastEntry = pred;
    } else {
      setPredecessor(succ, pred);
    }
  }

  @Override
  void insertEntry(int entryIndex, @ParametricNullness K key, int value, int hash) {
    super.insertEntry(entryIndex, key, value, hash);
    setSucceeds(lastEntry, entryIndex);
    setSucceeds(entryIndex, ENDPOINT);
  }

  @Override

    return Multisets.immutableEntry(entry.getElement(), entry.getCount());
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  /**
   * A sensible definition of {@link #lastEntry()} in terms of {@code
   * descendingMultiset().entrySet().iterator()}.
   *

  @Override
  public int count(@Nullable Object element) {
    return forward.count(element);
  }

  @Override
  public @Nullable Entry<E> firstEntry() {
    return forward.lastEntry();
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return forward.firstEntry();
  }

  @Override
  public int size() {
    return forward.size();
  }

  @Override
  public ImmutableSortedSet<E> elementSet() {

    }
    return result;
  }

  @Override
  public @Nullable Entry<E> firstEntry() {
    return delegate().firstEntry();
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {

    assertNull(navigableMap.higherEntry(k0()));
    assertNull(navigableMap.higherKey(k0()));
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMapLast() {
    assertNull(navigableMap.lastEntry());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptyMapPollLast() {
    assertNull(navigableMap.pollLastEntry());
  }