* method.
 *
 * <p>The {@code standard} methods and any collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Louis Wasserman
 */
@ElementTypesAreNonnullByDefault
public abstract class ForwardingSortedMultiset<E extends @Nullable Object>
    extends ForwardingMultiset<E> implements SortedMultiset<E> {
  /** Constructor for use by subclasses. */