@Test
  public void testScheduleFixedRateCallable() throws Exception {
    assertThat(submitted.getCount()).isZero();

    assertThat(running.getCount()).isZero();
    assertThat(completed.getCount()).isZero();
    assertThat(duration.getCount()).isZero();

    assertThat(scheduledOnce.getCount()).isZero();
    assertThat(scheduledRepetitively.getCount()).isZero();
    assertThat(scheduledOverrun.getCount()).isZero();
    assertThat(percentOfPeriod.getCount()).isZero();

    ScheduledFuture<?> theFuture =
        instrumentedScheduledExecutor.scheduleAtFixedRate(
            new Runnable() {
              public void run() {
                assertThat(submitted.getCount()).isZero();

                assertThat(running.getCount()).isEqualTo(1);

                assertThat(scheduledOnce.getCount()).isEqualTo(0);
                assertThat(scheduledRepetitively.getCount()).isEqualTo(1);

                try {
                  TimeUnit.MILLISECONDS.sleep(50);
                } catch (InterruptedException ex) {
                  Thread.currentThread().interrupt();
                }

                return;
              }
            },
            10L,
            10L,
            TimeUnit.MILLISECONDS);

    TimeUnit.MILLISECONDS.sleep(100);
    theFuture.cancel(true);
    TimeUnit.MILLISECONDS.sleep(100);

    assertThat(submitted.getCount()).isZero();

    assertThat(running.getCount()).isZero();
    assertThat(completed.getCount()).isNotEqualTo(0);
    assertThat(duration.getCount()).isNotEqualTo(0);
    assertThat(duration.getSnapshot().size()).isNotEqualTo(0);

    assertThat(scheduledOnce.getCount()).isZero();
    assertThat(scheduledRepetitively.getCount()).isEqualTo(1);
    assertThat(scheduledOverrun.getCount()).isNotEqualTo(0);
    assertThat(percentOfPeriod.getCount()).isNotEqualTo(0);
  }
  @Test
  public void testScheduleCallable() throws Exception {
    assertThat(submitted.getCount()).isZero();

    assertThat(running.getCount()).isZero();
    assertThat(completed.getCount()).isZero();
    assertThat(duration.getCount()).isZero();

    assertThat(scheduledOnce.getCount()).isZero();
    assertThat(scheduledRepetitively.getCount()).isZero();
    assertThat(scheduledOverrun.getCount()).isZero();
    assertThat(percentOfPeriod.getCount()).isZero();

    final Object obj = new Object();

    ScheduledFuture<Object> theFuture =
        instrumentedScheduledExecutor.schedule(
            new Callable<Object>() {
              public Object call() {
                assertThat(submitted.getCount()).isZero();

                assertThat(running.getCount()).isEqualTo(1);
                assertThat(completed.getCount()).isZero();
                assertThat(duration.getCount()).isZero();

                assertThat(scheduledOnce.getCount()).isEqualTo(1);
                assertThat(scheduledRepetitively.getCount()).isZero();
                assertThat(scheduledOverrun.getCount()).isZero();
                assertThat(percentOfPeriod.getCount()).isZero();

                return obj;
              }
            },
            10L,
            TimeUnit.MILLISECONDS);

    assertThat(theFuture.get()).isEqualTo(obj);

    assertThat(submitted.getCount()).isZero();

    assertThat(running.getCount()).isZero();
    assertThat(completed.getCount()).isEqualTo(1);
    assertThat(duration.getCount()).isEqualTo(1);
    assertThat(duration.getSnapshot().size()).isEqualTo(1);

    assertThat(scheduledOnce.getCount()).isEqualTo(1);
    assertThat(scheduledRepetitively.getCount()).isZero();
    assertThat(scheduledOverrun.getCount()).isZero();
    assertThat(percentOfPeriod.getCount()).isZero();
  }
  @Test
  public void testScheduleRunnable() throws Exception {
    assertThat(submitted.getCount()).isZero();

    assertThat(running.getCount()).isZero();
    assertThat(completed.getCount()).isZero();
    assertThat(duration.getCount()).isZero();

    assertThat(scheduledOnce.getCount()).isZero();
    assertThat(scheduledRepetitively.getCount()).isZero();
    assertThat(scheduledOverrun.getCount()).isZero();
    assertThat(percentOfPeriod.getCount()).isZero();

    ScheduledFuture<?> theFuture =
        instrumentedScheduledExecutor.schedule(
            new Runnable() {
              public void run() {
                assertThat(submitted.getCount()).isZero();

                assertThat(running.getCount()).isEqualTo(1);
                assertThat(completed.getCount()).isZero();
                assertThat(duration.getCount()).isZero();

                assertThat(scheduledOnce.getCount()).isEqualTo(1);
                assertThat(scheduledRepetitively.getCount()).isZero();
                assertThat(scheduledOverrun.getCount()).isZero();
                assertThat(percentOfPeriod.getCount()).isZero();
              }
            },
            10L,
            TimeUnit.MILLISECONDS);

    theFuture.get();

    assertThat(submitted.getCount()).isZero();

    assertThat(running.getCount()).isZero();
    assertThat(completed.getCount()).isEqualTo(1);
    assertThat(duration.getCount()).isEqualTo(1);
    assertThat(duration.getSnapshot().size()).isEqualTo(1);

    assertThat(scheduledOnce.getCount()).isEqualTo(1);
    assertThat(scheduledRepetitively.getCount()).isZero();
    assertThat(scheduledOverrun.getCount()).isZero();
    assertThat(percentOfPeriod.getCount()).isZero();
  }