@Override
    public void notifyNewValue(@CheckForNull V newValue) {
      if (newValue != null) {
        // The pending load was clobbered by a manual write.
        // Unblock all pending gets, and have them return the new value.
        set(newValue);
      } else {
        // The pending load was removed. Delay notifications until loading completes.
        oldValue = unset();
      }

    final AtomicInteger callCount = new AtomicInteger();
    // tells the computing thread when to start computing
    final CountDownLatch computeSignal = new CountDownLatch(1);
    // tells the main thread when computation is pending
    final CountDownLatch secondSignal = new CountDownLatch(1);
    // tells the main thread when the second get has started
    final CountDownLatch thirdSignal = new CountDownLatch(1);

      if (!isNullOrEmpty(pendingDescription)) {
        builder.append("PENDING, info=[").append(pendingDescription).append("]");
      } else if (isDone()) {
        addDoneString(builder);
      } else {
        builder.append("PENDING");
      }
    }
    return builder.append("]").toString();
  }

  /**

/**
 * An entry in a reference map.
 *
 * <p>Entries in the map can be in the following states:
 *
 * <p>Valid:
 *
 * <ul>
 *   <li>Live: valid key/value are set
 *   <li>Loading: loading is pending
 * </ul>
 *
 * <p>Invalid:
 *
 * <ul>
 *   <li>Expired: time expired (key/value may still be set)
 *   <li>Collected: key/value was partially collected, but not yet cleaned up

            "CombinedFuture@\\w+\\[status=PENDING,"
                + " info=\\[futures=\\[SettableFuture@\\w+\\[status=PENDING],"
                + " SettableFuture@\\w+\\[status=PENDING]]]]");
    Integer integerPartial = 1;
    futureInteger.set(integerPartial);
    assertThat(futureResult.toString())
        .matches(
            "CombinedFuture@\\w+\\[status=PENDING,"

     * `CollectionFuture.values`). This might be a no-op: If this future completed during
     * handleAllCompleted(), they will already have been nulled out. But in the case of
     * whenAll*().call*(), this future may be pending until the callback runs -- or even longer in
     * the case of callAsync(), which waits for the callback's returned future to complete.
     */
    releaseResources(ALL_INPUT_FUTURES_PROCESSED);
  }

  /**

   * tasks. Second, the returned list will always be empty, as any submitted task is considered to
   * have started execution. This applies also to tasks given to {@code invokeAll} or {@code
   * invokeAny} which are pending serial execution, even the subset of the tasks that have not yet
   * started execution. It is unclear from the {@code ExecutorService} specification if these should

   * source, the returned source will be empty. If {@code offset + length} is greater than the size
   * of this source, the returned source will contain the slice starting at {@code offset} and
   * ending at the end of this source.
   *
   * @throws IllegalArgumentException if {@code offset} or {@code length} is negative
   */
  public ByteSource slice(long offset, long length) {

  }

  @GwtIncompatible // QueuingRemovalListener
  public void testRemovalNotification_clear() throws InterruptedException {
    // If a clear() happens while a computation is pending, we should not get a removal
    // notification.

    final AtomicBoolean shouldWait = new AtomicBoolean(false);
    final CountDownLatch computingLatch = new CountDownLatch(1);

      int nextPermitsToAcquire = Math.max(1, random.nextInt(permits));
      permits -= nextPermitsToAcquire;
      rateLimiter.acquire(nextPermitsToAcquire);
    }
    rateLimiter.acquire(1); // to repay for any pending debt
    return NANOSECONDS.toMillis(stopwatch.instant - startTime);
  }

  private void assertEvents(String... events) {
    assertEquals(Arrays.toString(events), stopwatch.readEventsAndClear());
  }