@Override
        Iterator<Entry<E>> entryIterator() {
          return backingMultiset.descendingMultiset().entrySet().iterator();
        }
      };
    }

    @Override
    public NavigableSet<E> elementSet() {
      return new StandardElementSet();
    }

    @Override
    public Entry<E> firstEntry() {
      return standardFirstEntry();
    }

    @Override
    public Entry<E> lastEntry() {

    sortedMultiset = (SortedMultiset<E>) getMultiset();
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMultisetFirst() {
    assertNull(sortedMultiset.firstEntry());
    try {
      sortedMultiset.elementSet().first();
      fail();
    } catch (NoSuchElementException e) {
    }
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptyMultisetPollFirst() {

      }
      return JdkBackedImmutableMultiset.create(contents.entrySet());
    }
  }

  static final class ElementSet<E> extends ImmutableSet.Indexed<E> {
    private final List<Entry<E>> entries;
    // TODO(cpovirk): @Weak?
    private final Multiset<E> delegate;

    ElementSet(List<Entry<E>> entries, Multiset<E> delegate) {
      this.entries = entries;
      this.delegate = delegate;
    }

                    }
                    return builder.build().elementSet().asList();
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {
                    return Ordering.natural().sortedCopy(insertionOrder);
                  }
                })
            .named("ImmutableSortedMultiset.elementSet.asList")
            .withFeatures(

          parentBuilder) {
    return SetTestSuiteBuilder.using(
            new ElementSetGenerator<E>(parentBuilder.getSubjectGenerator()))
        .named(getName() + ".elementSet")
        .withFeatures(computeElementSetFeatures(parentBuilder.getFeatures()))
        .suppressing(parentBuilder.getSuppressedTests())
        .withSetUp(parentBuilder.getSetUp())

    assertContainsAllOf(
        keys.entrySet(), Multisets.immutableEntry((K) null, 2), Multisets.immutableEntry(k1(), 1));
  }

  public void testKeysElementSet() {
    assertEquals(multimap().keySet(), multimap().keys().elementSet());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testKeysRemove() {
    int original = multimap().keys().remove(k0(), 1);
    assertEquals(Math.max(original - 1, 0), multimap().get(k0()).size());
  }

    assertContainsAllOf(
        keys.entrySet(), Multisets.immutableEntry((K) null, 2), Multisets.immutableEntry(k1(), 1));
  }

  public void testKeysElementSet() {
    assertEquals(multimap().keySet(), multimap().keys().elementSet());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testKeysRemove() {
    int original = multimap().keys().remove(k0(), 1);
    assertEquals(Math.max(original - 1, 0), multimap().get(k0()).size());
  }

        return delegate().setCount(element, oldCount, newCount);
      }
    }

    @Override
    public Set<E> elementSet() {
      synchronized (mutex) {
        if (elementSet == null) {
          elementSet = typePreservingSet(delegate().elementSet(), mutex);
        }
        return elementSet;
      }
    }

    @Override
    public Set<Multiset.Entry<E>> entrySet() {
      synchronized (mutex) {

        @Override
        Iterator<Entry<E>> entryIterator() {
          return backingMultiset.descendingMultiset().entrySet().iterator();
        }
      };
    }

    @Override
    public NavigableSet<E> elementSet() {
      return new StandardElementSet();
    }

    @Override
    public Entry<E> firstEntry() {
      return standardFirstEntry();
    }

    @Override
    public Entry<E> lastEntry() {

  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E element) {
    RegularImmutableSortedSet<E> elementSet =
        (RegularImmutableSortedSet<E>) ImmutableSortedSet.of(element);
    long[] cumulativeCounts = {0, 1};
    return new RegularImmutableSortedMultiset<>(elementSet, cumulativeCounts, 0, 1);
  }

  /**