Deletes a subscription.
            
 Declaration Syntax
 Declaration Syntax| C# | 
UnsubscribeResponse Unsubscribe( UnsubscribeRequest request )
 Parameters
 Parameters- request (UnsubscribeRequest)
- Unsubscribe request
 Return Value
 Return ValueUnsubscribe  Response from the service
 Remarks
 Remarks
            If the subscription requires authentication for deletion, only the owner
            of the subscription or the its topic's owner can unsubscribe, and an AWS
            signature is required.
            If the Unsubscribe call does not require authentication and the requester is not
            the subscription owner, a final cancellation message is delivered to the
            endpoint, so that the endpoint owner can easily resubscribe to the topic if
            the Unsubscribe request was unintended.