如何在创建ecs.LoadBalancedFargateService时指定子网

from aws_cdk import aws_ec2 as ec2
from aws_cdk import aws_ecs as ecs
from aws_cdk import aws_ecs_patterns as ecs_patterns
from aws_cdk import core

app = core.App()

stack = core.Stack(app, "MyStack", env={'region': 'us-west-2'})

vpc = ec2.Vpc(
    stack, "MyVpc",
    max_azs=2,
    subnet_configuration=[
        ec2.SubnetConfiguration(
            name="Public",
            subnet_type=ec2.SubnetType.PUBLIC
        ),
        ec2.SubnetConfiguration(
            name="Private",
            subnet_type=ec2.SubnetType.PRIVATE
        )
    ]
)

service = ecs_patterns.LoadBalancedFargateService(
    stack, "MyFargateService",
    vpc=vpc,
    memory_limit_mib=512,
    cpu=256,
    task_image_options={
        'image': ecs.ContainerImage.from_registry("amazon/amazon-ecs-sample")
    }
)

app.synth()