try {
      future.get(timeoutMillis, MILLISECONDS);
      shouldThrow();
    } catch (TimeoutException success) {
    } catch (Exception e) {
      threadUnexpectedException(e);
    } finally {
      future.cancel(true);
    }
    assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
  }

  /** Fails with message "should throw exception". */
  public void shouldThrow() {
    fail("Should throw exception");
  }

    consumer.accept(new ValueAndCloser<C>(closingFuture));
  }

  /**
   * Attempts to cancel execution of this step. This attempt will fail if the step has already
   * completed, has already been cancelled, or could not be cancelled for some other reason. If
   * successful, and this step has not started when {@code cancel} is called, this step should never
   * run.
   *

    // stop it.
    blockingCallable.waitForStart();

    // This time, cancel the future for the first task. The task remains running, only the future
    // is cancelled.
    future1.cancel(false);

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    // (This is the assertion that fails.)
    assertThat(future2.isDone()).isFalse();

    // stop it.
    blockingCallable.waitForStart();

    // This time, cancel the future for the first task. The task remains running, only the future
    // is cancelled.
    future1.cancel(false);

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    // (This is the assertion that fails.)
    assertThat(future2.isDone()).isFalse();

    secondBarrier.await();
    firstBarrier.await();
    assertEquals(2, scheduler.scheduleCounter.get());
    shouldWait.set(false);
    secondBarrier.await();
    future.cancel(false);
  }

  public void testCustomSchedulerServiceStop() throws Exception {
    TestAbstractScheduledCustomService service = new TestAbstractScheduledCustomService();
    service.startAsync().awaitRunning();

      assertThat(timer.elapsed(MILLISECONDS)).isAtLeast(10L);

      // If even the first one wasn't there, clean up so that the next test doesn't see an element.
      producerThread.cancel(true);
      producer.doneProducing.await();
      if (drained == 0) {
        q.poll(); // not necessarily there if producer was interrupted
      }
    }
  }

    try {
      future.get(timeoutMillis, MILLISECONDS);
      shouldThrow();
    } catch (TimeoutException success) {
    } catch (Exception e) {
      threadUnexpectedException(e);
    } finally {
      future.cancel(true);
    }
    assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
  }

  /** Fails with message "should throw exception". */
  public void shouldThrow() {
    fail("Should throw exception");
  }

    secondBarrier.await();
    firstBarrier.await();
    assertEquals(2, scheduler.scheduleCounter.get());
    shouldWait.set(false);
    secondBarrier.await();
    future.cancel(false);
  }

  public void testCustomSchedulerServiceStop() throws Exception {
    TestAbstractScheduledCustomService service = new TestAbstractScheduledCustomService();
    service.startAsync().awaitRunning();

   * I/O resource, it should generally be safe in the case of a resource that's being used only for
   * reading, such as an {@code InputStream}. Unlike with writable resources, there's no chance that
   * a failure that occurs when closing the stream indicates a meaningful problem such as a failure
   * to flush all bytes to the underlying resource.
   *

      public void run() {
        thirdSignal.countDown();
        result.set(1, cache.getUnchecked(key));
        doneSignal.countDown();
      }
    }.start();

    // give the second get a chance to run; it is okay for this to be racy
    // as the end result should be the same either way
    thirdSignal.await();
    Thread.yield();

    // Expand!
    CacheTesting.forceExpandSegment(cache, key);