* the {@link ByteSource} returned by {@link #asByteSource} is finalized.
   *
   * @param fileThreshold the number of bytes before the stream should switch to buffering to a file
   * @param resetOnFinalize if true, the {@link #reset} method will be called when the {@link
   *     ByteSource} returned by {@link #asByteSource} is finalized.
   * @throws IllegalArgumentException if {@code fileThreshold} is negative
   */

    GcFinalization.awaitClear(finalizableWeakReference);

    Field sepFrqUserFinalizedF = sepFrqUserC.getField("finalized");
    Semaphore finalizeCount = (Semaphore) sepFrqUserFinalizedF.get(null);
    boolean finalized = finalizeCount.tryAcquire(5, TimeUnit.SECONDS);
    assertTrue(finalized);

    Field sepFrqUserFrqF = sepFrqUserC.getField("frq");
    Closeable frq = (Closeable) sepFrqUserFrqF.get(null);

    GcFinalization.awaitClear(finalizableWeakReference);

    Field sepFrqUserFinalizedF = sepFrqUserC.getField("finalized");
    Semaphore finalizeCount = (Semaphore) sepFrqUserFinalizedF.get(null);
    boolean finalized = finalizeCount.tryAcquire(5, TimeUnit.SECONDS);
    assertTrue(finalized);

    Field sepFrqUserFrqF = sepFrqUserC.getField("frq");
    Closeable frq = (Closeable) sepFrqUserFrqF.get(null);

   * separate method to make it somewhat more likely to be unreachable.
   */
  private static void createUnreachableLatchFinalizer(CountDownLatch latch) {
    Object unused =
        new Object() {
          @SuppressWarnings("removal") // b/260137033
          @Override
          protected void finalize() {
            latch.countDown();
          }

   * separate method to make it somewhat more likely to be unreachable.
   */
  private static void createUnreachableLatchFinalizer(CountDownLatch latch) {
    Object unused =
        new Object() {
          @SuppressWarnings("removal") // b/260137033
          @Override
          protected void finalize() {
            latch.countDown();
          }

    write(out, data, 0, 100, true);
    final File file = out.getFile();
    assertEquals(100, file.length());
    assertTrue(file.exists());
    out.close();

    // Make sure that finalize deletes the file
    out = null;

    // times out and throws RuntimeException on failure
    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          @Override

    implements FinalizableReference {
  /**
   * Constructs a new finalizable weak reference.
   *
   * @param referent to weakly reference
   * @param queue that should finalize the referent
   */
  protected FinalizableWeakReference(@CheckForNull T referent, FinalizableReferenceQueue queue) {
    super(referent, queue.queue);
    queue.cleanUp();
  }

    write(out, data, 0, 100, true);
    final File file = out.getFile();
    assertEquals(100, file.length());
    assertTrue(file.exists());
    out.close();

    // Make sure that finalize deletes the file
    out = null;

    // times out and throws RuntimeException on failure
    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          @Override

    implements FinalizableReference {
  /**
   * Constructs a new finalizable soft reference.
   *
   * @param referent to softly reference
   * @param queue that should finalize the referent
   */
  protected FinalizableSoftReference(@CheckForNull T referent, FinalizableReferenceQueue queue) {
    super(referent, queue.queue);
    queue.cleanUp();
  }

    oos.writeObject(map);
    oos.flush();

    int mapSize = bytes.size();
    oos.writeObject(keySet);
    oos.writeObject(values);
    oos.close();

    int finalSize = bytes.size();

    assertThat(finalSize - mapSize).isLessThan(100);
  }

  // TODO: Re-enable this test after moving to new serialization format in ImmutableMap.
  @J2ktIncompatible
  @GwtIncompatible // SerializableTester