*/
  public static final MediaType VND_REAL_AUDIO = createConstant(AUDIO_TYPE, "vnd.rn-realaudio");

  /**
   * WAVE format, as defined by <a href="https://tools.ietf.org/html/rfc2361">RFC 2361</a>.
   *
   * @since 20.0
   */
  public static final MediaType VND_WAVE_AUDIO = createConstant(AUDIO_TYPE, "vnd.wave");

  /* video types */
  public static final MediaType MP4_VIDEO = createConstant(VIDEO_TYPE, "mp4");

   */
  public static final MediaType VND_REAL_AUDIO = createConstant(AUDIO_TYPE, "vnd.rn-realaudio");

  /**
   * WAVE format, as defined by <a href="https://tools.ietf.org/html/rfc2361">RFC 2361</a>.
   *
   * @since 20.0
   */
  public static final MediaType VND_WAVE_AUDIO = createConstant(AUDIO_TYPE, "vnd.wave");

  /* video types */
  public static final MediaType MP4_VIDEO = createConstant(VIDEO_TYPE, "mp4");

// Some Android 5.0.x Samsung devices have bugs in JDK reflection APIs that cause
// getDeclaredField to throw a NoSuchFieldException when the field is definitely there.
// Since this class only needs CAS on one field, we can avoid this bug by extending AtomicReference
// instead of using an AtomicReferenceFieldUpdater. This reference stores Thread instances
// and DONE/INTERRUPTED - they have a common ancestor of Runnable.

    assertThat(keySet).containsExactly(1, 3, 6, 8);

    // get fails to save 1, put saves 3
    cache.asMap().put(3, -3);
    getAll(cache, asList(1));
    CacheTesting.drainRecencyQueues(cache);
    ticker.advance(1, MILLISECONDS);
    assertThat(keySet).containsExactly(6, 8, 3);

    // get(K, Callable) fails to save 8, replace saves 6
    cache.asMap().replace(6, -6);

  private final transient int size;

  /*
   * We have some considerable complexity in these create methods because of
   * Builder.buildKeepingLast(). The same Builder might be called with buildKeepingLast() and then
   * buildOrThrow(), or vice versa. So in particular, if we modify alternatingKeysAndValues to
   * eliminate duplicate keys (for buildKeepingLast()) then we have to ensure that a later call to

    /*
     * Since we use AtomicReferenceFieldUpdaterAtomicHelper by default, we'll "obviously" use it
     * even when Unsafe isn't available. But it's nice to have a check here to make sure that
     * nothing somehow goes wrong as the JDK restricts access to Unsafe.
     */
    checkHelperVersion(NO_UNSAFE, "AtomicReferenceFieldUpdaterAtomicHelper");
    /*

  // Timed Get
  // There are a few design constraints to consider
  // * We want to be responsive to small timeouts, unpark() has non trivial latency overheads (I
  //   have observed 12 micros on 64-bit linux systems to wake up a parked thread). So if the
  //   timeout is small we shouldn't park(). This needs to be traded off with the cpu overhead of

  // Timed Get
  // There are a few design constraints to consider
  // * We want to be responsive to small timeouts, unpark() has non trivial latency overheads (I
  //   have observed 12 micros on 64-bit linux systems to wake up a parked thread). So if the
  //   timeout is small we shouldn't park(). This needs to be traded off with the cpu overhead of

   * `INADEQUATE_SECURITY`.
   */
  HTTP_2("h2"),

  /**
   * Cleartext HTTP/2 with no "upgrade" round trip. This option requires the client to have prior
   * knowledge that the server supports cleartext HTTP/2.
   *
   * See also [Starting HTTP/2 with Prior Knowledge][rfc_7540_34].
   *
   * [rfc_7540_34]: https://datatracker.ietf.org/doc/html/rfc7540#autoid-10
   */

  @SuppressWarnings("Immutable")
  private final long[] array;

  /*
   * TODO(kevinb): evaluate the trade-offs of going bimorphic to save these two fields from most
   * instances. Note that the instances that would get smaller are the right set to care about
   * optimizing, because the rest have the option of calling `trimmed`.
   */

  private final transient int start; // it happens that we only serialize instances where this is 0