* if {@code n == 0}.
   *
   * <p><b>Warning:</b> the result takes <i>O(n log n)</i> space, so use cautiously.
   *
   * <p>This uses an efficient binary recursive algorithm to compute the factorial with balanced
   * multiplies. It also removes all the 2s from the intermediate products (shifting them back in at
   * the end).
   *
   * @throws IllegalArgumentException if {@code n < 0}
   */

 *           // Services have been initialized and are healthy, start accepting requests...
 *         }
 *         public void failure(Service service) {
 *           // Something failed, at this point we could log it, notify a load balancer, or take
 *           // some other action.  For now we will just exit.
 *           System.exit(1);
 *         }
 *       },
 *       MoreExecutors.directExecutor());
 *