isInterruptibleRegistered.countDown();
            try {
              new CountDownLatch(1).await(); // the interrupt will wake us up
            } catch (InterruptedException ie) {
              // continue
            }
            LockSupport.unpark(Thread.currentThread()); // simulate a spurious wakeup.
            return null;
          }

          @Override
          boolean isDone() {
            return false;

            isInterruptibleRegistered.countDown();
            try {
              new CountDownLatch(1).await(); // the interrupt will wake us up
            } catch (InterruptedException ie) {
              // continue
            }
            LockSupport.unpark(Thread.currentThread()); // simulate a spurious wakeup.
            return null;
          }

          @Override
          boolean isDone() {
            return false;

   * occur except for those produced by awaitUninterruptibly itself in response to interrupts.
   *
   * This isn't guaranteed to work, so any further spurious wakeups would probably cause failures in
   * tests that assert that a certain amount of time has passed, that the method returned `false`,
   * or even that an interrupt occurred (if the spurious wakeup happens before the interrupt).
   *

   * occur except for those produced by awaitUninterruptibly itself in response to interrupts.
   *
   * This isn't guaranteed to work, so any further spurious wakeups would probably cause failures in
   * tests that assert that a certain amount of time has passed, that the method returned `false`,
   * or even that an interrupt occurred (if the spurious wakeup happens before the interrupt).
   *

    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    LockSupport.unpark(waiter2); // spurious wakeup
    waiter2.awaitWaiting(); // should eventually re-park

    future.set(null);
    waiter2.join();
  }

    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    LockSupport.unpark(waiter2); // spurious wakeup
    waiter2.awaitWaiting(); // should eventually re-park

    future.set(null);
    waiter2.join();
  }

  }

  private List<Entry<Object, Object>> warmUp(LoadingCache<Object, Object> cache) {
    return warmUp(cache, WARMUP_MIN, WARMUP_MAX);
  }

  /**
   * Returns the entries that were added to the map, so they won't fall out of a map with weak or
   * soft references until the caller drops the reference to the returned entries.
   */
  private List<Entry<Object, Object>> warmUp(

    List<Integer> callOrder = new ArrayList<>();

    class FakeOp implements Runnable {
      final int op;

      FakeOp(int op) {
        this.op = op;
      }

      @Override
      public void run() {
        callOrder.add(op);
      }
    }

    e.execute(new FakeOp(0));
    e.execute(new FakeOp(1));
    e.execute(new FakeOp(2));
    fakePool.runAll();

    for (int i = 0; i < 8; i++) {
      limiter.acquire(); // // #1
    }
    stopwatch.sleepMillis(4500); // #2: back to cold state (warmup period + repay last acquire)
    for (int i = 0; i < 3; i++) { // only three steps, we're somewhere in the warmup period
      limiter.acquire(); // #3
    }

    limiter.setRate(4.0); // double the rate!

    for (int i = 0; i < 8; i++) {
      limiter.acquire(); // // #1
    }
    stopwatch.sleepMillis(4500); // #2: back to cold state (warmup period + repay last acquire)
    for (int i = 0; i < 3; i++) { // only three steps, we're somewhere in the warmup period
      limiter.acquire(); // #3
    }

    limiter.setRate(4.0); // double the rate!