}

  /**
   * {@link AtomicHelper} based on {@link sun.misc.Unsafe}.
   *
   * <p>Static initialization of this class will fail if the {@link sun.misc.Unsafe} object cannot
   * be accessed.
   */
  @SuppressWarnings({"sunapi", "removal"}) // b/318391980
  private static final class UnsafeAtomicHelper extends AtomicHelper {
    static final sun.misc.Unsafe UNSAFE;
    static final long LISTENERS_OFFSET;