wrong release function in async example

找到包含 release(item) 函数的 async 示例，并检查排队的请求如何接收已释放的项目。验证队列交接以及 free/available 计数，然后执行该示例的 release 行为，以确认直接交给排队用户的项目不会同时被计为 free。

  release(item) {
    const index = this.items.indexOf(item);
    if (index < 0) throw new Error('Pool: release unexpected item');
    if (this.free[index]) throw new Error('Pool: release not captured');
    this.free[index] = true;
    this.available++;
    if (this.queue.length > 0) {
      const { resolve, timer } = this.queue.shift();
      clearTimeout(timer);
      if (resolve) setTimeout(resolve, 0, item);
    }
  }

error - we should not free released item if we resolve it for user in queue

  release(item) {
    const index = this.items.indexOf(item);
    if (index < 0) throw new Error('Pool: release unexpected item');
    if (this.free[index]) throw new Error('Pool: release not captured');
    if (this.queue.length > 0) {
      const { resolve, timer } = this.queue.shift();
      clearTimeout(timer);
      if (resolve) setTimeout(resolve, 0, item);
    } else { 
      this.free[index] = true;
      this.available++;
    }
  }