//    you entered with, and it doesn't actually matter.
  //
  // 2. Since you can enter the monitor without a guard at all, some
  //    places you'll have monitor.enter()/monitor.leave() and other
  //    places you'll have guard.enter()/guard.leave() even though
  //    it's the same lock being acquired underneath. Always using
  //    monitor.enterXXX()/monitor.leave() will make it really clear

   * with arbitrary Unicode text. It is mostly intended for use with text that is known to be safe
   * for use with it (such as all-ASCII text) and for simple debugging text. When using this method,
   * consider the following:
   *
   * <ul>
   *   <li>it may split surrogate pairs
   *   <li>it may split characters and combining characters
   *   <li>it does not consider word boundaries

   *
   * @param formal The type whose type variables or itself is mapped to other type(s). It's almost
   *     always a bug if {@code formal} isn't a type variable and contains no type variable. Make
   *     sure you are passing the two parameters in the right order.
   * @param actual The type that the formal type variable(s) are mapped to. It can be or contain yet

  /**
   * Returns the given string if it is non-null; the empty string otherwise.
   *
   * @param string the string to test and possibly return
   * @return {@code string} itself if it is non-null; {@code ""} if it is null
   */
  public static String nullToEmpty(@CheckForNull String string) {
    return Platform.nullToEmpty(string);
  }

  /**
   * Returns the given string if it is nonempty; {@code null} otherwise.
   *

     * stack so that it is returned by the next call to {@link Iterator#next()}. If the element is
     * not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can

   *     no effect on the multimap.
   */
  @CanIgnoreReturnValue
  Collection<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values);

  /**
   * Removes all values associated with the key {@code key}.
   *
   * <p>Once this method returns, {@code key} will not be mapped to any values, so it will not

   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *
   * <p>This method is not type-safe, as it may be called on elements that are not mutually
   * comparable.
   *

 * #minValue} and {@link #maxValue} should also be overridden for bounded types.
 *
 * <p>A discrete domain always represents the <i>entire</i> set of values of its type; it cannot
 * represent partial domains such as "prime integers" or "strings of length 5."
 *
 * <p>See the Guava User Guide section on <a href=
 * "https://github.com/google/guava/wiki/RangesExplained#discrete-domains">{@code

    }
  }

  /**
   * Returns a hash function implementing FarmHash's Fingerprint64, an open-source algorithm.
   *
   * <p>This is designed for generating persistent fingerprints of strings. It isn't
   * cryptographically secure, but it produces a high-quality hash with fewer collisions than some
   * alternatives we've used in the past.
   *
   * <p>FarmHash fingerprints are encoded by {@link HashCode#asBytes} in little-endian order. This

    assertEquals(1, runLatch.getCount());
  }

  public void testListenerCalledOnCancelFromRunning() throws Exception {
    exec.execute(task);
    runLatch.await();

    // Task has started up, cancel it while it's running.
    task.cancel(true);
    assertTrue(task.isDone());
    assertTrue(task.isCancelled());
    assertEquals(1, taskLatch.getCount());

    // Wait for the listeners to be called.