SMALL_DELAY_MS = SHORT_DELAY_MS * 5;
    MEDIUM_DELAY_MS = SHORT_DELAY_MS * 10;
    LONG_DELAY_MS = SHORT_DELAY_MS * 200;
  }

  /**
   * Returns a timeout in milliseconds to be used in tests that verify that operations block or time
   * out.
   */
  long timeoutMillis() {
    return SHORT_DELAY_MS / 4;
  }

    SMALL_DELAY_MS = SHORT_DELAY_MS * 5;
    MEDIUM_DELAY_MS = SHORT_DELAY_MS * 10;
    LONG_DELAY_MS = SHORT_DELAY_MS * 200;
  }

  /**
   * Returns a timeout in milliseconds to be used in tests that verify that operations block or time
   * out.
   */
  long timeoutMillis() {
    return SHORT_DELAY_MS / 4;
  }

    assertTrue(tryAcquireUninterruptibly(semaphore, LONG_DELAY_MS, MILLISECONDS));
    assertTimeNotPassed(stopwatch, LONG_DELAY_MS);
  }

  public void testTryAcquireTimeoutNoInterruptNotExpired() {
    TimedSemaphore semaphore = TimedSemaphore.createWithDelay(20);
    semaphore.tryAcquireSuccessfully(LONG_DELAY_MS);
    assertNotInterrupted();
  }

  boolean called = false;

  private void assertSingleCallWithCorrectParameters(
      Runnable command, long initialDelay, long delay, TimeUnit unit) {
    assertFalse(called); // only called once.
    called = true;
    assertEquals(INITIAL_DELAY, initialDelay);
    assertEquals(DELAY, delay);
    assertEquals(UNIT, unit);
    assertEquals(testRunnable, command);
  }

  public void testFixedRateSchedule() {

     * A value object that represents an absolute delay until a task should be invoked.
     *
     * @author Luke Sandberg
     * @since 11.0
     */
    protected static final class Schedule {

      private final long delay;
      private final TimeUnit unit;

      /**
       * @param delay the time from now to delay execution
       * @param unit the time unit of the delay parameter
       */

    assertTrue(tryAcquireUninterruptibly(semaphore, LONG_DELAY_MS, MILLISECONDS));
    assertTimeNotPassed(stopwatch, LONG_DELAY_MS);
  }

  public void testTryAcquireTimeoutNoInterruptNotExpired() {
    TimedSemaphore semaphore = TimedSemaphore.createWithDelay(20);
    semaphore.tryAcquireSuccessfully(LONG_DELAY_MS);
    assertNotInterrupted();
  }

  boolean called = false;

  private void assertSingleCallWithCorrectParameters(
      Runnable command, long initialDelay, long delay, TimeUnit unit) {
    assertFalse(called); // only called once.
    called = true;
    assertEquals(INITIAL_DELAY, initialDelay);
    assertEquals(DELAY, delay);
    assertEquals(UNIT, unit);
    assertEquals(testRunnable, command);
  }

  public void testFixedRateSchedule() {

        (expectedOutcome == Outcome.HANG)
            ? EXPECTED_HANG_DELAY_MILLIS
            : UNEXPECTED_HANG_DELAY_MILLIS;
    boolean hung =
        !awaitUninterruptibly(callCompletedLatch, hangDelayMillis, TimeUnit.MILLISECONDS);
    if (hung) {
      assertEquals(expectedOutcome, Outcome.HANG);
    } else {
      assertNull(task.get(UNEXPECTED_HANG_DELAY_MILLIS, TimeUnit.MILLISECONDS));
    }
  }

  @Override

      notifyStopped();
    }
  }

  /*
   * A NoOp service that will delay the startup and shutdown notification for a configurable amount
   * of time.
   */
  private static class NoOpDelayedService extends NoOpService {
    private long delay;

    public NoOpDelayedService(long delay) {
      this.delay = delay;
    }

    @Override
    protected void doStart() {
      new Thread() {

 * additional configuration, permits will be distributed at a fixed rate, defined in terms of
 * permits per second. Permits will be distributed smoothly, with the delay between individual
 * permits being adjusted to ensure that the configured rate is maintained.
 *
 * <p>It is possible to configure a {@code RateLimiter} to have a warmup period during which time