Set<E> elementSet = getMultiset().elementSet();
    assertFalse(elementSet.contains(e3()));
    getMultiset().add(e3(), 4);
    assertTrue(elementSet.contains(e3()));
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testElementSetReflectsRemove() {
    Set<E> elementSet = getMultiset().elementSet();
    assertTrue(elementSet.contains(e0()));

  /** A skeleton implementation for {@link SortedMultiset#elementSet}. */
  @SuppressWarnings("JdkObsolete") // TODO(b/6160855): Switch GWT emulations to NavigableSet.
  static class ElementSet<E extends @Nullable Object> extends Multisets.ElementSet<E>
      implements SortedSet<E> {
    @Weak private final SortedMultiset<E> multiset;

    ElementSet(SortedMultiset<E> multiset) {
      this.multiset = multiset;
    }

    this.length = 0;
  }

  RegularImmutableSortedMultiset(
      RegularImmutableSortedSet<E> elementSet, long[] cumulativeCounts, int offset, int length) {
    this.elementSet = elementSet;
    this.cumulativeCounts = cumulativeCounts;
    this.offset = offset;
    this.length = length;
  }

  private int getCount(int index) {
    return (int) (cumulativeCounts[offset + index + 1] - cumulativeCounts[offset + index]);
  }

  @LazyInit private transient @Nullable Set<E> elementSet;

  @Override
  public Set<E> elementSet() {
    Set<E> result = elementSet;
    if (result == null) {
      elementSet = result = createElementSet();
    }
    return result;
  }

  /**
   * Creates a new instance of this multiset's element set, which will be returned by {@link
   * #elementSet()}.
   */
  Set<E> createElementSet() {

    Set<E> elementSet = getMultiset().elementSet();
    assertFalse(elementSet.contains(e3()));
    getMultiset().add(e3(), 4);
    assertTrue(elementSet.contains(e3()));
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testElementSetReflectsRemove() {
    Set<E> elementSet = getMultiset().elementSet();
    assertTrue(elementSet.contains(e0()));

      }
    }
    return 0;
  }

  @Override
  public int size() {
    return size;
  }

  @Override
  public ImmutableSet<E> elementSet() {
    ImmutableSet<E> result = elementSet;
    return (result == null) ? elementSet = new ElementSet<>(Arrays.asList(entries), this) : result;
  }

  @Override
  Entry<E> getEntry(int index) {
    return entries[index];
  }

  @Override

 * to ensure binary compatibility with older Guava versions that specified {@code elementSet()} to
 * return {@code SortedSet}.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible
interface SortedMultisetBridge<E extends @Nullable Object> extends Multiset<E> {
  @Override
  SortedSet<E> elementSet();

  /** A skeleton implementation for {@link SortedMultiset#elementSet}. */
  @SuppressWarnings("JdkObsolete") // TODO(b/6160855): Switch GWT emulations to NavigableSet.
  static class ElementSet<E extends @Nullable Object> extends Multisets.ElementSet<E>
      implements SortedSet<E> {
    @Weak private final SortedMultiset<E> multiset;

    ElementSet(SortedMultiset<E> multiset) {
      this.multiset = multiset;
    }

  @LazyInit private transient @Nullable Set<E> elementSet;

  @Override
  public Set<E> elementSet() {
    Set<E> result = elementSet;
    if (result == null) {
      elementSet = result = createElementSet();
    }
    return result;
  }

  /**
   * Creates a new instance of this multiset's element set, which will be returned by {@link
   * #elementSet()}.
   */
  Set<E> createElementSet() {

    this.length = 0;
  }

  RegularImmutableSortedMultiset(
      RegularImmutableSortedSet<E> elementSet, long[] cumulativeCounts, int offset, int length) {
    this.elementSet = elementSet;
    this.cumulativeCounts = cumulativeCounts;
    this.offset = offset;
    this.length = length;
  }

  private int getCount(int index) {
    return (int) (cumulativeCounts[offset + index + 1] - cumulativeCounts[offset + index]);
  }