请说说你对TypeScript中mixin的理解

"Mixin 是一种在 TypeScript 中用于实现代码复用和组合的技术。通过 Mixin，我们可以将多个类的特性组合到一个类中，从而实现代码的复用和扩展。在 TypeScript 中，Mixin 主要通过类的继承和交叉类型来实现。

type Constructor<T = {}> = new (...args: any[]) => T;

function Timestamped<TBase extends Constructor>(Base: TBase) {
  return class extends Base {
    timestamp = Date.now();
  };
}

class User {
  name: string;

  constructor(name: string) {
    this.name = name;
  }
}

const TimestampedUser = Timestamped(User);
const user = new TimestampedUser(\"Alice\");
console.log(user.name); // \"Alice\"
console.log(user.timestamp); // Current timestamp

type Constructor<T = {}> = new (...args: any[]) => T;

function Savable<TBase extends Constructor>(Base: TBase) {
  return class extends Base {
    save() {
      // Save the instance
    }
  };
}

class User {
  name: string;

  constructor(name: string) {
    this.name = name;
  }
}

const SavableUser = Savable(User);
const user = new SavableUser(\"Bob\");
user.save();

type Constructor<T = {}> = new (...args: any[]) => T;

function Timestamped<TBase extends Constructor>(Base: TBase) {
  return class extends Base {
    timestamp = Date.now();
  };
}

function Savable<TBase extends Constructor>(Base: TBase) {
  return class extends Base {
    save() {
      // Save the instance
    };
  };
}

class User {
  name: string;

  constructor(name: string) {
    this.name = name;
  }
}

const TimestampedSavableUser = Timestamped(Savable(User));
const user = new TimestampedSavableUser(\"Charlie\");
user.save();
console.log(user.timestamp); // Current timestamp

通过 Mixin，我们可以灵活地组合不同类的特性，实现更多样化和灵活化的代码复用和扩展，提高代码的可维护性和可扩展性。"