@Override
    public E pop() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.pop();
    }

    @Override
    public Iterator<E> descendingIterator() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.descendingIterator();
    }

    private static final long serialVersionUID = 0;
  }

  @SuppressWarnings("CheckReturnValue")
  public void testHoldsLockOnAllOperations() {

    @Override
    public E pop() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.pop();
    }

    @Override
    public Iterator<E> descendingIterator() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.descendingIterator();
    }

    private static final long serialVersionUID = 0;
  }

  @SuppressWarnings("CheckReturnValue")
  public void testHoldsLockOnAllOperations() {

    checkNotNull(toBoundType);
    return tailMultiset(fromElement, fromBoundType).headMultiset(toElement, toBoundType);
  }

  abstract Iterator<Entry<E>> descendingEntryIterator();

  Iterator<E> descendingIterator() {
    return Multisets.iteratorImpl(descendingMultiset());
  }

  @LazyInit private transient @Nullable SortedMultiset<E> descendingMultiset;

  @Override

    return -1;
  }

  @Override
  public UnmodifiableIterator<C> iterator() {
    return emptyIterator();
  }

  @GwtIncompatible // NavigableSet
  @Override
  public UnmodifiableIterator<C> descendingIterator() {
    return emptyIterator();
  }

  @Override
  boolean isPartialView() {
    return false;
  }

  @Override
  public boolean isEmpty() {
    return true;
  }

    }

    @Override
    public Iterator<E> descendingIterator() {
      return Iterators.filter(unfiltered().descendingIterator(), predicate);
    }

    @Override
    @ParametricNullness
    public E last() {
      return Iterators.find(unfiltered().descendingIterator(), predicate);
    }

    @Override
    public NavigableSet<E> subSet(

      return wrap(getSortedSetDelegate().descendingSet());
    }

    @Override
    public Iterator<V> descendingIterator() {
      return new WrappedIterator(getSortedSetDelegate().descendingIterator());
    }

    @Override
    public NavigableSet<V> subSet(
        @ParametricNullness V fromElement,
        boolean fromInclusive,
        @ParametricNullness V toElement,

    }

    @Override
    public NavigableSet<E> descendingSet() {
      return new NavigableElementSet<>(multiset().descendingMultiset());
    }

    @Override
    public Iterator<E> descendingIterator() {
      return descendingSet().iterator();
    }

    @Override
    public @Nullable E pollFirst() {
      return getElementOrNull(multiset().pollFirstEntry());
    }

    @Override

  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return elements.iterator();
  }

  @GwtIncompatible // NavigableSet
  @Override
  public UnmodifiableIterator<E> descendingIterator() {
    return elements.reverse().iterator();
  }

  @Override
  public Spliterator<E> spliterator() {
    return asList().spliterator();
  }

  @Override

        return equalsOrThrow(previous, last) ? null : domain.next(previous);
      }
    };
  }

  @GwtIncompatible // NavigableSet
  @Override
  public UnmodifiableIterator<C> descendingIterator() {
    return new AbstractSequentialIterator<C>(last()) {
      final C first = first();

      @Override
      protected @Nullable C computeNext(C previous) {

    public @Nullable E ceiling(E e) {
      synchronized (mutex) {
        return delegate().ceiling(e);
      }
    }

    @Override
    public Iterator<E> descendingIterator() {
      return delegate().descendingIterator(); // manually synchronized
    }

    transient @Nullable NavigableSet<E> descendingSet;

    @Override
    public NavigableSet<E> descendingSet() {