在测试代码中模拟NetworkLoadBalancer时，需要确保依赖的其他资源（例如SecurityGroup，Subnet等）都已经正确模拟。以下是一个例如测试NetworkLoadBalancer创建的代码示例，其中使用了Sinon.js来模拟Lambda和CloudFormation资源：

import { expect } from 'chai';
import * as sinon from 'sinon';
import * as cdk from 'aws-cdk-lib';
import * as cloudformation from 'aws-cdk-lib/aws-cloudformation';
import * as ec2 from 'aws-cdk-lib/aws-ec2';
import * as elbv2 from 'aws-cdk-lib/aws-elasticloadbalancingv2';

import { MyStack } from '../lib/MyStack';

describe('MyStack', () => {
  let app: cdk.App;
  let stack: MyStack;

  beforeEach(() => {
    app = new cdk.App();
    stack = new MyStack(app, 'MyStack');
  });

  afterEach(() => {
    sinon.restore();
  });

  it('should create Network Load Balancer', async () => {
    const subnet1 = new ec2.CfnSubnet(stack, 'Subnet1', {
      vpcId: 'vpc-id',
      availabilityZone: 'us-west-2a',
      cidrBlock: '10.0.1.0/24',
    });
    const subnet2 = new ec2.CfnSubnet(stack, 'Subnet2', {
      vpcId: 'vpc-id',
      availabilityZone: 'us-west-2b',
      cidrBlock: '10.0.2.0/24',
    });
    const securityGroup = new ec2.CfnSecurityGroup(stack, 'SecurityGroup', {
      vpcId: 'vpc-id',
      groupDescription: 'My Security Group',
      securityGroupIngress: [],
    });

    // create a stub for CloudFormation updateStack
    const updateStackStub = sinon.stub(cloudformation.CloudFormation.prototype, 'updateStack').returns({
      promise: () => Promise.resolve(),
    });

    // create a mock for lambda function
    const functionStub = sinon.stub().returns({
      FunctionArn: 'arn:aws