Gets and sets the property DefaultSubnetId. 
            
            The stack's default subnet ID.         All instances will be launched into this subnet
            unless you specify otherwise when you create the instance.         If you also specify
            a value for  CopyC#, the subnet must be in that zone.
                    For more information, see CreateStack.
CopyC#, the subnet must be in that zone.
                    For more information, see CreateStack.  
            DefaultAvailabilityZone
 Declaration Syntax
 Declaration Syntax| C# | 
public string DefaultSubnetId { get; set; }