Sets the ARN of the subscription's topic.
            
 Declaration Syntax
 Declaration Syntax| C# | 
[ObsoleteAttribute("The With methods are obsolete and will be removed in version 2 of the AWS SDK for .NET. See http://aws.amazon.com/sdkfornet/#version2 for more information.")] public Subscription WithTopicArn( string topicArn )
 Parameters
 Parameters- topicArn (String)
- The ARN of the subscription's topic.
 Return Value
 Return Valuethis instance