return new TimedPutQueue(countdownInMillis);
    }

    private TimedPutQueue(long countdownInMillis) {
      this.queue = new ArrayBlockingQueue<>(1);
      assertTrue(queue.offer("blocksPutCallsUntilRemoved"));
      this.completed = new Completion(countdownInMillis);
      scheduleEnableWrites(this.queue, countdownInMillis);
    }