final TestCloseable closeable2 = new TestCloseable("closeable2");
  final TestCloseable closeable3 = new TestCloseable("closeable3");
  final TestCloseable closeable4 = new TestCloseable("closeable4");

  final Waiter waiter = new Waiter();
  final CountDownLatch futureCancelled = new CountDownLatch(1);
  final Exception exception = new Exception();
  final Closeable mockCloseable = Mockito.mock(Closeable.class);

  @Override

  volatile @Nullable Waiter waitersField;

  /** Non-volatile write of the thread to the {@link Waiter#thread} field. */
  private static void putThread(Waiter waiter, Thread newValue) {
    ATOMIC_HELPER.putThread(waiter, newValue);
  }

  /** Non-volatile write of the waiter to the {@link Waiter#next} field. */
  private static void putNext(Waiter waiter, @Nullable Waiter newValue) {

  volatile @Nullable Waiter waitersField;

  /** Non-volatile write of the thread to the {@link Waiter#thread} field. */
  private static void putThread(Waiter waiter, Thread newValue) {
    ATOMIC_HELPER.putThread(waiter, newValue);
  }

  /** Non-volatile write of the waiter to the {@link Waiter#next} field. */
  private static void putNext(Waiter waiter, @Nullable Waiter newValue) {

    // Check that we wait long enough anyway (presumably as long as MAX_VALUE nanos):
    TimedWaiterThread waiter = new TimedWaiterThread(future, Long.MAX_VALUE, SECONDS);
    waiter.start();
    waiter.awaitWaiting();

    future.set(1);
    waiter.join();
  }

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testSetNull() throws Exception {
    future.set(null);

    WaiterThread waiter1 = new WaiterThread(future);
    waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();

    WaiterThread waiter1 = new WaiterThread(future);
    waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();

    hashFunctions[0] = Murmur3_128HashFunction.GOOD_FAST_HASH_128;
    int seed = GOOD_FAST_HASH_SEED;
    for (int i = 1; i < hashFunctionsNeeded; i++) {
      seed += 1500450271; // a prime; shouldn't matter
      hashFunctions[i] = murmur3_128(seed);
    }
    return new ConcatenatedHashFunction(hashFunctions);
  }

  /**
   * Used to randomize {@link #goodFastHash} instances, so that programs which persist anything

 [conscrypt]: https://github.com/google/conscrypt/
 [get_example]: https://raw.github.com/square/okhttp/master/samples/guide/src/main/java/okhttp3/guide/GetExample.java
 [kotlin]: https://kotlinlang.org/
 [okhttp3_pro]: https://raw.githubusercontent.com/square/okhttp/master/okhttp/src/main/resources/META-INF/proguard/okhttp3.pro
 [okhttp]: https://square.github.io/okhttp/

    assertEquals(1, numCalls.get());
  }

  /*
   * Under Android, MyError propagates up and fails the test?
   *
   * TODO(b/218700094): Does this matter to prod users, or is it just a feature of our testing
   * environment? If the latter, maybe write a custom Executor that avoids failing the test when it
   * sees an Error?
   */
  @AndroidIncompatible
  public void testTaskThrowsError() throws Exception {

        assertArgumentNotNull("props", props);
        assertArgumentNotNull("writer", writer);

        try {
            props.store(writer, comments);
        } catch (final IOException e) {
            throw new IORuntimeException(e);
        }
    }

    /**