*/
@SuppressWarnings("serial") // uses writeReplace, not default serialization
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class DescendingImmutableSortedMultiset<E> extends ImmutableSortedMultiset<E> {
  private final transient ImmutableSortedMultiset<E> forward;

  DescendingImmutableSortedMultiset(ImmutableSortedMultiset<E> forward) {
    this.forward = forward;
  }

  @Override
  public int count(@CheckForNull Object element) {

    if (result == null) {
      return descendingMultiset =
          this.isEmpty()
              ? emptyMultiset(Ordering.from(comparator()).reverse())
              : new DescendingImmutableSortedMultiset<E>(this);
    }
    return result;
  }

  /**
   * {@inheritDoc}
   *
   * <p>This implementation is guaranteed to throw an {@link UnsupportedOperationException}.
   *