final int millis;
    volatile boolean completed;

    public SleepingRunnable(int millis) {
      this.millis = millis;
    }

    @Override
    public void run() {
      try {
        Thread.sleep(millis);
      } catch (InterruptedException wontHappen) {
        throw new AssertionError();
      }
      completed = true;
    }
  }

    thread.start();
    thread.awaitWaiting();
    thread.suspend();
    // Sleep for enough time to add 1500 milliseconds of overwait to the get() call.
    long toWaitMillis = 3500 - TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - thread.startTime);
    Thread.sleep(toWaitMillis);
    thread.setPriority(Thread.MAX_PRIORITY);
    thread.resume();
    thread.join();

      Object oldValue = ref.get();
      if (oldValue == null) {
        expectedComputations++;
      }
      ref = new WeakReference<>(cache.getUnchecked(1));
      oldValue = null;
      Thread.sleep(i);
      System.gc();
    }
    assertEquals(expectedComputations, countingLoader.getCount());

    for (int i = 0; i < iterations; i++) {
      // The entry should get garbage collected and recomputed.

    Interrupter(Thread threadToInterrupt) {
      this.threadToInterrupt = threadToInterrupt;
    }

    @Override
    public void run() {
      try {
        Thread.sleep(100);
      } catch (InterruptedException e) {
        throw new AssertionError();
      } finally {
        threadToInterrupt.interrupt();
      }
    }
  }

    // Service b startup takes at least 353 millis, but starting the timer is delayed by at least
    // 150 milliseconds. so in a perfect world the timing would be 353-150=203ms, but since either
    // of our sleep calls can be arbitrarily delayed we should just assert that there is a time
    // recorded.
    assertThat(startupTimes.get(b)).isNotNull();
  }

  public void testServiceStartStop() {

      this.everyMillis = everyMillis;
      this.interruptee = interruptee;
    }

    @Override
    public void run() {
      while (true) {
        try {
          Thread.sleep(everyMillis);
        } catch (InterruptedException e) {
          // ok. just stop sleeping.
        }
        if (shouldStop) {
          break;
        }
        interruptee.interrupt();
      }
    }

          public void run() {
            taskDone = true;
          }
        };
    ScheduledFuture<?> future =
        TestingExecutors.noOpScheduledExecutor().schedule(task, 10, TimeUnit.MILLISECONDS);
    Thread.sleep(20);
    assertFalse(taskDone);
    assertFalse(future.isDone());
  }

  public void testNoOpScheduledExecutorShutdown() {
    ListeningScheduledExecutorService executor = TestingExecutors.noOpScheduledExecutor();

            } else if (behavior == 1) { // return null
              computeNullCount.incrementAndGet();
              return null;
            } else if (behavior == 2) { // slight delay before returning
              Thread.sleep(5);
              computeCount.incrementAndGet();
              return key;
            } else {
              computeCount.incrementAndGet();
              return key;
            }
          }
        };