* <p>If you are escaping input in arbitrary successive chunks, then it is not generally safe to
   * use this method. If an input string ends with an unmatched high surrogate character, then this
   * method will throw {@link IllegalArgumentException}. You should ensure your input is valid <a
   * href="http://en.wikipedia.org/wiki/UTF-16">UTF-16</a> before calling this method.
   *

  public void testGet() throws ExecutionException {
    when(mock.get("key")).thenReturn(Boolean.TRUE);
    assertSame(Boolean.TRUE, forward.get("key"));
  }

  public void testGetUnchecked() {
    when(mock.getUnchecked("key")).thenReturn(Boolean.TRUE);
    assertSame(Boolean.TRUE, forward.getUnchecked("key"));
  }

  public void testGetAll() throws ExecutionException {

   * consideration by {@link #maximumWeight(long)} when determining which entries to evict, and use
   * of this method requires a corresponding call to {@link #maximumWeight(long)} prior to calling
   * {@link #build}. Weights are measured and recorded when entries are inserted into the cache, and
   * are thus effectively static during the lifetime of a cache entry.
   *

 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
 *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
 *       to "undo" {@link ElementTypesAreNonnullByDefault}. It is the best we can do for Kotlin
 *       under our current constraints.

 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
 *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
 *       to "undo" {@link ElementTypesAreNonnullByDefault}. It is the best we can do for Kotlin
 *       under our current constraints.

   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if
   * {@code map} and the instances generated by {@code factory} are. Concurrent read operations will
   * work correctly. To allow concurrent update operations, wrap the multimap with a call to {@link
   * #synchronizedMultimap}.
   *
   * <p>Call this method only when the simpler methods {@link ArrayListMultimap#create()}, {@link

   */
  @ForOverride
  protected abstract void doStop();

  /**
   * This method is called by {@link #stopAsync} when the service is still starting (i.e. {@link
   * #startAsync} has been called but {@link #notifyStarted} has not). Subclasses can override the
   * method to cancel pending work and then call {@link #notifyStopped} to stop the service.
   *

  }

  enum RunningState {
    NOT_RUN,
    CANCELLED,
    STARTED,
  }

  /**
   * This class helps avoid a StackOverflowError when large numbers of tasks are submitted with
   * {@link MoreExecutors#directExecutor}. Normally, when the first future completes, all the other
   * tasks would be called recursively. Here, we detect that the delegate executor is executing

   *
   * // Falling back to a zero counter in case an exception happens when
   * // processing the RPC to fetch counters.
   * ListenableFuture<Integer> faultTolerantFuture = Futures.catching(
   *     fetchCounterFuture, FetchException.class, x -> 0, directExecutor());
   * }</pre>
   *
   * <p>When selecting an executor, note that {@code directExecutor} is dangerous in some cases. See

   * when inputFuture returns VALID_INPUT_DATA, and sets the exception to EXCEPTION in all other
   * cases.
   */
  protected abstract ListenableFuture<T> buildChainingFuture(ListenableFuture<Integer> inputFuture);

  /**
   * Override to return the result when VALID_INPUT_DATA is passed in to the chaining
   * listenableFuture
   */