return lazyWeakCustom(stripes, WeakSafeReadWriteLock::new);
  }
  /**
   * ReadWriteLock implementation whose read and write locks retain a reference back to this lock.
   * Otherwise, a reference to just the read lock or just the write lock would not suffice to ensure
   * the {@code ReadWriteLock} is retained.
   */
  private static final class WeakSafeReadWriteLock implements ReadWriteLock {