throw new AssertionError("should never be called");
  }

  /**
   * @deprecated Internal method, use {@link #entrySet()}.
   */
  @Deprecated
  @Override
  public Set<Multiset.Entry<E>> createEntrySet() {
    return new EntrySet();
  }

  @Override
  int distinctElements() {
    return countMap.size();
  }

  @Override
  public boolean isEmpty() {
    return countMap.isEmpty();