protected void finalize() {
            future.set(null);
          }
        };
    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.awaitDone(future);
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());
  }

  public void testAwaitDone_future_cancel() {
    final SettableFuture<@Nullable Void> future = SettableFuture.create();
    Object unused =
        new Object() {

            }
            throw e;
        }
    }


    /**
     * {@inheritDoc}
     *
     * @see jcifs.smb.DirFileEntryEnumIteratorBase#isDone()
     */
    @Override
    protected boolean isDone () {
        return this.response.isEndOfSearch();
    }


    /**
     * @throws CIFSException
     */
    @Override

@ElementTypesAreNonnullByDefault
abstract class InterruptibleTask<T extends @Nullable Object> implements Runnable {

  @Override
  public void run() {
    T result = null;
    Throwable error = null;
    if (isDone()) {
      return;
    }
    try {
      result = runInterruptibly();
    } catch (Throwable t) {
      error = t;
    }
    if (error == null) {

    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Start the task to put it in the RUNNING state.  Have to use a separate
    // thread because the task will block on the task latch after unblocking
    // the run latch.
    exec.execute(task);
    runLatch.await();
    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

        }

        if ( !last && !isDone() ) {
            if ( !fetchMore() ) {
                doClose();
                return null;
            }
            this.ridx = 0;
            return advance(true);
        }
        return null;
    }


    protected abstract FileEntry open () throws CIFSException;


    protected abstract boolean isDone ();

    assertFalse(task.isDone());
    task.run();
    assertTrue(task.isDone());
    assertFalse(task.isCancelled());
    assertEquals(2, getDone(task).intValue());
  }

  public void testCancelled() throws Exception {
    TrustedListenableFutureTask<Integer> task = TrustedListenableFutureTask.create(returning(2));
    assertFalse(task.isDone());
    task.cancel(false);
    assertTrue(task.isDone());

    assertTrue(future.isDone());
    assertFalse(future.isCancelled());

    assertEquals(expectedValue, future.get());
  }

  public void testCancelledFuture() throws InterruptedException, ExecutionException {
    assertTrue(future.isDone());
    assertTrue(future.isCancelled());

    assertTrue(latch.await(5, SECONDS));
    assertTrue(future.isDone());
    assertTrue(future.isCancelled());

    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Start the task to put it in the RUNNING state.  Have to use a separate
    // thread because the task will block on the task latch after unblocking
    // the run latch.
    exec.execute(task);
    runLatch.await();
    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    }
  }

  /**
   * Tests that a canceled future throws a cancellation exception.
   *
   * <p>This method checks the cancel, isCancelled, and isDone methods.
   */
  public void testCanceledFutureThrowsCancellation() throws Exception {

    assertFalse(future.isDone());
    assertFalse(future.isCancelled());

    CountDownLatch successLatch = new CountDownLatch(1);

    // Check that the future has been set properly.
    assertFalse(future.isDone());
    assertFalse(future.isCancelled());
    assertThrows(TimeoutException.class, () -> future.get(0, MILLISECONDS));
    nested.set("foo");
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());
    assertEquals("foo", future.get());
  }

  private static class Foo {}