A comma-separated list of subnet identifiers of Amazon Virtual Private Clouds (Amazon VPCs). If you specify subnets and Availability Zones
            with this call, ensure that the subnets' Availability Zones match the Availability Zones specified. For information on launching your Auto
            Scaling group into Amazon VPC subnets, see Launch Auto Scaling Instances into Amazon
            VPC in the Auto Scaling Developer Guide .
             
            
Constraints:
 Declaration Syntax
 Declaration Syntax| C# | 
public string VPCZoneIdentifier { get; set; }