前端面试题 - 105. 实现一个Promise的延迟执行函数（Deferred），包括resolve和reject方法。

关键点：构造函数中将promise、resolve、reject挂在到this上。

class Deferred {
  constructor() {
    this.promise = new Promise((resolve, reject) => {
      this.resolve = resolve;
      this.reject = reject;
    });
  }
}