}

  @CollectionSize.Require(SEVERAL)
  public void testDescendingNavigation() {
    List<Entry<K, V>> descending = new ArrayList<>(navigableMap.descendingMap().entrySet());
    Collections.reverse(descending);
    assertEquals(entries, descending);
  }

  @CollectionSize.Require(absent = ZERO)
  public void testHeadMapExclusive() {

  }

  @CollectionSize.Require(SEVERAL)
  public void testDescendingNavigation() {
    List<Entry<K, V>> descending = new ArrayList<>(navigableMap.descendingMap().entrySet());
    Collections.reverse(descending);
    assertEquals(entries, descending);
  }

  @CollectionSize.Require(absent = ZERO)
  public void testHeadMapExclusive() {

    }

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

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

    @Override
    public NavigableSet<K> navigableKeySet() {
      return new StandardNavigableKeySet();
    }

    @Override