assertEquals(c, navigableMap.pollLastEntry());
    assertEquals(entries.subList(0, entries.size() - 1), copyToList(navigableMap.entrySet()));
  }

  @MapFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(SEVERAL)
  public void testPollLastUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> navigableMap.pollLastEntry());
  }

  @CollectionSize.Require(SEVERAL)

    }
    return result;
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {
    return forwardMultiset().pollLastEntry();
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {
    return forwardMultiset().pollFirstEntry();
  }

  @Override
  public SortedMultiset<E> headMultiset(E toElement, BoundType boundType) {

    }
    return result;
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {
    return forwardMultiset().pollLastEntry();
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {
    return forwardMultiset().pollFirstEntry();
  }

  @Override
  public SortedMultiset<E> headMultiset(@ParametricNullness E toElement, BoundType boundType) {

    }
    return result;
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {
    return forwardMultiset().pollLastEntry();
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {
    return forwardMultiset().pollFirstEntry();
  }

  @Override
  public SortedMultiset<E> headMultiset(@ParametricNullness E toElement, BoundType boundType) {

      result = Multisets.immutableEntry(result.getElement(), result.getCount());
      entryIterator.remove();
      return result;
    }
    return null;
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {
    Iterator<Entry<E>> entryIterator = descendingEntryIterator();
    if (entryIterator.hasNext()) {
      Entry<E> result = entryIterator.next();

     */

    @Override
    public @Nullable Entry<K, V> pollFirstEntry() {
      return standardPollFirstEntry();
    }

    @Override
    public @Nullable Entry<K, V> pollLastEntry() {
      return standardPollLastEntry();
    }

    @Override
    public NavigableMap<K, V> descendingMap() {
      return new StandardDescendingMap();
    }

    @Override

    assertThat(map.descendingKeySet()).containsExactly("two", "three", "one").inOrder();

    assertEquals(mapEntry("one", 3), map.pollFirstEntry());
    assertEquals(mapEntry("two", 3), map.pollLastEntry());
    assertEquals(1, map.size());
  }

  @GwtIncompatible // NavigableMap
  public void testAsMapNavigableReadsThrough() {
    NavigableSet<String> strings = Sets.newTreeSet();

    assertThat(map.descendingKeySet()).containsExactly("two", "three", "one").inOrder();

    assertEquals(mapEntry("one", 3), map.pollFirstEntry());
    assertEquals(mapEntry("two", 3), map.pollLastEntry());
    assertEquals(1, map.size());
  }

  @GwtIncompatible // NavigableMap
  public void testAsMapNavigableReadsThrough() {
    NavigableSet<String> strings = Sets.newTreeSet();

    public @Nullable Entry<K, V2> pollFirstEntry() {
      return transformEntry(fromMap().pollFirstEntry());
    }

    @Override
    public @Nullable Entry<K, V2> pollLastEntry() {
      return transformEntry(fromMap().pollLastEntry());
    }

    @Override
    public NavigableMap<K, V2> subMap(
        @ParametricNullness K fromKey,
        boolean fromInclusive,

    public @Nullable Entry<K, V2> pollFirstEntry() {
      return transformEntry(fromMap().pollFirstEntry());
    }

    @Override
    public @Nullable Entry<K, V2> pollLastEntry() {
      return transformEntry(fromMap().pollLastEntry());
    }

    @Override
    public NavigableMap<K, V2> subMap(
        @ParametricNullness K fromKey,
        boolean fromInclusive,