final Segment<K, V>[] newSegmentArray(int ssize) {
    return (Segment<K, V>[]) new Segment<?, ?>[ssize];
  }

  // Inner Classes

  /**
   * Segments are specialized versions of hash tables. This subclass inherits from ReentrantLock
   * opportunistically, just to simplify some locking and avoid separate construction.
   */
  @SuppressWarnings("serial") // This class is never serialized.