import java.util.concurrent.TimeoutException;

/**
 * A {@link Future} implementation which always throws directly from calls to {@code get()} (i.e.
 * not wrapped in {@code ExecutionException}. For just a normal failure, use {@link
 * SettableFuture}).
 *
 * <p>Useful for testing the behavior of Future utilities against odd futures.
 *
 * @author Anthony Zana
 */
@GwtCompatible

    return ref == null ? Optional.<T>absent() : Optional.of(enumClass.cast(ref.get()));
  }

  static String formatCompact4Digits(double value) {
    return String.format(Locale.ROOT, "%.4g", value);
  }

  static boolean stringIsNullOrEmpty(@CheckForNull String string) {
    return string == null || string.isEmpty();
  }

  /**

    integralBuilder.addAll(Doubles.asList(0.0, -0.0, Double.MAX_VALUE, -Double.MAX_VALUE));
    // Add small multiples of MIN_VALUE and MIN_NORMAL
    for (int scale = 1; scale <= 4; scale++) {
      for (double d : Doubles.asList(Double.MIN_VALUE, Double.MIN_NORMAL)) {
        fractionalBuilder.add(d * scale).add(-d * scale);
      }
    }
    for (int i = Double.MIN_EXPONENT; i <= Double.MAX_EXPONENT; i++) {

    assertEquals(0, stopwatch.elapsed(MILLISECONDS));
    ticker.advance(1);
    assertEquals(1, stopwatch.elapsed(MILLISECONDS));
  }

  @J2ktIncompatible // TODO(b/259213718): Switch J2kt to String.format("%.4g") once that's supported
  public void testToString() {
    stopwatch.start();
    assertEquals("0.000 ns", stopwatch.toString());
    ticker.advance(1);
    assertEquals("1.000 ns", stopwatch.toString());

  private URLClassLoader classReloader;
  private Class<?> settableFutureClass;
  private Class<?> abstractFutureClass;

  @Override
  protected void setUp() throws Exception {
    // Load the "normal" copy of SettableFuture and related classes.
    SettableFuture<?> unused = SettableFuture.create();
    // Hack to load AbstractFuture et. al. in a new classloader so that it re-reads the cancellation

        for (int i = 0; i < objectsNum; i++) {
          objects.add(new Object());
        }

        Iterable<?> locks = striped.bulkGet(objects);
        assertTrue(Ordering.natural().onResultOf(Functions.forMap(indexByLock)).isOrdered(locks));

        // check idempotency
        Iterable<?> locks2 = striped.bulkGet(objects);
        assertEquals(Lists.newArrayList(locks), Lists.newArrayList(locks2));
      }
    }

 *
 * <p>As with {@link Preconditions}, {@code Verify} uses {@link Strings#lenientFormat} to format
 * error message template strings. This only supports the {@code "%s"} specifier, not the full range
 * of {@link java.util.Formatter} specifiers. However, note that if the number of arguments does not
 * match the number of occurrences of {@code "%s"} in the format string, {@code Verify} will still

      replaced with your own identifying information. (Don't include
      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

 * #stopAsync()} lifecycle methods to transition between states. Example services include
 * webservers, RPC servers and timers.
 *
 * <p>The normal lifecycle of a service is:
 *
 * <ul>
 *   <li>{@linkplain State#NEW NEW} -&gt;
 *   <li>{@linkplain State#STARTING STARTING} -&gt;
 *   <li>{@linkplain State#RUNNING RUNNING} -&gt;

 * </ol>
 *
 * <p><b>Other notes</b>
 *
 * <ul>
 *   <li>Usually, there is one testcase method per JSR166 method covering "normal" operation, and
 *       then as many exception-testing methods as there are exceptions the method can throw.
 *       Sometimes there are multiple tests per JSR166 method when the different "normal" behaviors
 *       differ significantly. And sometimes testcases cover multiple methods when they cannot be