expectAddFailure(sortedMultiset.tailMultiset(b.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), CLOSED), a);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), CLOSED), b);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), OPEN), a);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), OPEN), c);
  }

    expectAddFailure(sortedMultiset.tailMultiset(b.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), CLOSED), a);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), CLOSED), b);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), OPEN), a);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), OPEN), b);
    expectAddFailure(sortedMultiset.tailMultiset(c.getElement(), OPEN), c);
  }

      @ParametricNullness E upperBound,
      BoundType upperBoundType) {
    return tailMultiset(lowerBound, lowerBoundType).headMultiset(upperBound, upperBoundType);
  }

  @Override
  public SortedMultiset<E> tailMultiset(@ParametricNullness E lowerBound, BoundType boundType) {
    return delegate().tailMultiset(lowerBound, boundType);
  }

      E lowerBound, BoundType lowerBoundType, E upperBound, BoundType upperBoundType) {
    return tailMultiset(lowerBound, lowerBoundType).headMultiset(upperBound, upperBoundType);
  }

  @Override
  public SortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
    return delegate().tailMultiset(lowerBound, boundType);
  }

    @Override
    @CheckForNull
    public E ceiling(@ParametricNullness E e) {
      return getElementOrNull(multiset().tailMultiset(e, CLOSED).firstEntry());
    }

    @Override
    @CheckForNull
    public E higher(@ParametricNullness E e) {
      return getElementOrNull(multiset().tailMultiset(e, OPEN).firstEntry());
    }

    @Override
    public NavigableSet<E> descendingSet() {

    assertEquals(Integer.MAX_VALUE, ms.headMultiset("a", CLOSED).size());

    assertEquals(3, ms.tailMultiset("c", CLOSED).size());
    assertEquals(Integer.MAX_VALUE, ms.tailMultiset("b", CLOSED).size());
    assertEquals(Integer.MAX_VALUE, ms.tailMultiset("a", CLOSED).size());
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

    return forward;
  }

  @Override
  public ImmutableSortedMultiset<E> headMultiset(E upperBound, BoundType boundType) {
    return forward.tailMultiset(upperBound, boundType).descendingMultiset();
  }

  @Override
  public ImmutableSortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
    return forward.headMultiset(lowerBound, boundType).descendingMultiset();
  }

  @Override
  boolean isPartialView() {

        delegate().subMultiset(lowerBound, lowerBoundType, upperBound, upperBoundType));
  }

  @Override
  public SortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
    return Multisets.unmodifiableSortedMultiset(delegate().tailMultiset(lowerBound, boundType));
  }

  private static final long serialVersionUID = 0;

        delegate().subMultiset(lowerBound, lowerBoundType, upperBound, upperBoundType));
  }

  @Override
  public SortedMultiset<E> tailMultiset(@ParametricNullness E lowerBound, BoundType boundType) {
    return Multisets.unmodifiableSortedMultiset(delegate().tailMultiset(lowerBound, boundType));
  }

  private static final long serialVersionUID = 0;

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

  @Override
  public SortedMultiset<E> headMultiset(E toElement, BoundType boundType) {
    return forwardMultiset().tailMultiset(toElement, boundType).descendingMultiset();
  }

  @Override
  public SortedMultiset<E> subMultiset(
      E fromElement, BoundType fromBoundType, E toElement, BoundType toBoundType) {
    return forwardMultiset()