如何创建CDK NestedStack？

import * as cdk from 'aws-cdk-lib';
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as cloudformation from 'aws-cdk-lib/aws-cloudformation';

class MyNestedStack extends cloudformation.NestedStack {
  constructor(scope: cdk.Construct, id: string, props?: cdk.NestedStackProps) {
    super(scope, id, props);
    
    // 在构造函数中定义NestedStack的资源
    const bucket = new s3.Bucket(this, 'MyBucket', {
      // 设置Bucket的属性
    });
  }

  protected createStack(): cloudformation.Stack {
    // 在createStack方法中定义NestedStack的CloudFormation资源
    const stack = new cloudformation.Stack(this, 'MyStack', {
      // 设置Stack的属性
    });

    // 添加其他资源到Stack中
    stack.addResource('AWS::S3::BucketPolicy', {
      // 设置Bucket Policy的属性
    });

    return stack;
  }
}

class MyStack extends cdk.Stack {
  constructor(scope: cdk.Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // 创建NestedStack实例并将其添加到主Stack中
    const nestedStack = new MyNestedStack(this, 'MyNestedStack');
  }
}