How to use the @aws-cdk/aws-ec2.Subnet function in @aws-cdk/aws-ec2

const tagAllSubnets = (type: string, subnets: ec2.ISubnet[], tag: string) => {
      for (const subnet of subnets) {
        // if this is not a concrete subnet, attach a construct warning
        if (!ec2.Subnet.isVpcSubnet(subnet)) {
          // message (if token): "could not auto-tag public/private subnet with tag..."
          // message (if not token): "count not auto-tag public/private subnet xxxxx with tag..."
          const subnetID = Token.isUnresolved(subnet.subnetId) ? '' : ` ${subnet.subnetId}`;
          this.node.addWarning(`Could not auto-tag ${type} subnet${subnetID} with "${tag}=1", please remember to do this manually`);
          continue;
        }

        subnet.node.applyAspect(new Tag(tag, "1"));
      }
    };