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(max(original - 1, 0), multimap().get(k0()).size());
  }

      return JdkBackedImmutableMultiset.create(entries);
    }
  }

  @Override
  public int count(@Nullable Object element) {
    throw new AssertionError();
  }

  @Override
  public ImmutableSet<E> elementSet() {
    throw new AssertionError();
  }

  @Override
  Entry<E> getEntry(int index) {
    throw new AssertionError();
  }

  @Override
  boolean isPartialView() {
    throw new AssertionError();

        @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() {

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

  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMultisetFirst() {
    assertNull(sortedMultiset.firstEntry());
    assertThrows(NoSuchElementException.class, () -> sortedMultiset.elementSet().first());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptyMultisetPollFirst() {
    assertNull(sortedMultiset.pollFirstEntry());
  }

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

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

  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E e1) {
    RegularImmutableSortedSet<E> elementSet =
        (RegularImmutableSortedSet<E>) ImmutableSortedSet.of(e1);
    long[] cumulativeCounts = {0, 1};
    return new RegularImmutableSortedMultiset<>(elementSet, cumulativeCounts, 0, 1);
  }

  /**
   * Returns an immutable sorted multiset containing the given elements sorted by their natural

  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E e1) {
    RegularImmutableSortedSet<E> elementSet =
        (RegularImmutableSortedSet<E>) ImmutableSortedSet.of(e1);
    long[] cumulativeCounts = {0, 1};
    return new RegularImmutableSortedMultiset<>(elementSet, cumulativeCounts, 0, 1);
  }

  /**
   * Returns an immutable sorted multiset containing the given elements sorted by their natural

   *
   * <p>A common use for the element set is to find the number of distinct elements in the multiset:
   * {@code elementSet().size()}.
   *
   * @return a view of the set of distinct elements in this multiset
   */
  Set<E> elementSet();

  /**
   * Returns a view of the contents of this multiset, grouped into {@code Multiset.Entry} instances,

  }

  @LazyInit private transient @Nullable Reference<Multiset<N>> adjacentNodesReference;

  @Override
  public Set<N> adjacentNodes() {
    return Collections.unmodifiableSet(adjacentNodesMultiset().elementSet());
  }

  private Multiset<N> adjacentNodesMultiset() {
    Multiset<N> adjacentNodes = getReference(adjacentNodesReference);
    if (adjacentNodes == null) {