assertTrue(limiter.tryAcquire(0, SECONDS));
    assertFalse(limiter.tryAcquire(0, SECONDS));
    assertFalse(limiter.tryAcquire(0, SECONDS));
    stopwatch.sleepMillis(100);
    assertFalse(limiter.tryAcquire(0, SECONDS));
  }

  public void testTryAcquire_someWaitAllowed() {
    RateLimiter limiter = RateLimiter.create(5.0, stopwatch);
    assertTrue(limiter.tryAcquire(0, SECONDS));

   * second" (commonly referred to as <i>QPS</i>, queries per second).
   *
   * <p>The returned {@code RateLimiter} ensures that on average no more than {@code
   * permitsPerSecond} are issued during any given second, with sustained requests being smoothly
   * spread over each second. When the incoming request rate exceeds {@code permitsPerSecond} the

    future.set(1);
    assertEquals(1, future.get(-1, SECONDS).intValue());
  }

  @J2ktIncompatible
  @GwtIncompatible // threads
  public void testOverflowTimeout() throws Exception {
    // First, sanity check that naive multiplication would really overflow to a negative number:
    long nanosPerSecond = NANOSECONDS.convert(1, SECONDS);
    assertThat(nanosPerSecond * Long.MAX_VALUE).isLessThan(0L);

   *
   * How this works is best explained with an example:
   *
   * For a RateLimiter that produces 1 token per second, every second that goes by with the
   * RateLimiter being unused, we increase storedPermits by 1. Say we leave the RateLimiter unused
   * for 10 seconds (i.e., we expected a request at time X, but we are at time X + 10 seconds before
   * a request actually arrives; this is also related to the point made in the last paragraph), thus

      return;
    }
    long timeoutSeconds = timeoutSeconds();
    long deadline = System.nanoTime() + SECONDS.toNanos(timeoutSeconds);
    do {
      System.runFinalization();
      if (future.isDone()) {
        return;
      }
      System.gc();
      try {
        future.get(1L, SECONDS);
        return;
      } catch (CancellationException | ExecutionException ok) {
        return;

    assertTrue(limiter.tryAcquire(0, SECONDS));
    assertFalse(limiter.tryAcquire(0, SECONDS));
    assertFalse(limiter.tryAcquire(0, SECONDS));
    stopwatch.sleepMillis(100);
    assertFalse(limiter.tryAcquire(0, SECONDS));
  }

  public void testTryAcquire_someWaitAllowed() {
    RateLimiter limiter = RateLimiter.create(5.0, stopwatch);
    assertTrue(limiter.tryAcquire(0, SECONDS));

        "foo", getChecked(immediateFuture("foo"), TwoArgConstructorException.class, 0, SECONDS));
  }

  public void testGetCheckedTimed_interrupted() {
    SettableFuture<String> future = SettableFuture.create();
    Thread.currentThread().interrupt();
    try {
      getChecked(future, TwoArgConstructorException.class, 0, SECONDS);
      fail();
    } catch (TwoArgConstructorException expected) {

            ImmutableSet.of(
                DurationSpec.of(0, SECONDS), DurationSpec.of(1, SECONDS), DurationSpec.of(1, DAYS)))
        .withExpireAfterAccesses(
            ImmutableSet.of(
                DurationSpec.of(0, SECONDS), DurationSpec.of(1, SECONDS), DurationSpec.of(1, DAYS)))
        .withRefreshes(ImmutableSet.of(DurationSpec.of(1, SECONDS), DurationSpec.of(1, DAYS)));
  }

        "foo", getChecked(immediateFuture("foo"), TwoArgConstructorException.class, 0, SECONDS));
  }

  public void testGetCheckedTimed_interrupted() {
    SettableFuture<String> future = SettableFuture.create();
    Thread.currentThread().interrupt();
    try {
      getChecked(future, TwoArgConstructorException.class, 0, SECONDS);
      fail();
    } catch (TwoArgConstructorException expected) {

      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, TimeUnit.SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried
      barrier.await(1, TimeUnit.SECONDS);
    } finally {
      service.shutdown();
    }
  }

  public void testRejectedExecutionThrownWithMultipleCalls() throws Exception {