}

    private TimedTakeQueue(long countdownInMillis) {
      this.queue = new ArrayBlockingQueue<>(1);
      this.completed = new Completion(countdownInMillis);
      scheduleEnableReads(this.queue, countdownInMillis);
    }

    /** Perform a {@code take} and assert that operation completed in the expected timeframe. */
    void takeSuccessfully() {