Checks if ListSubscriptionsByTopicResult property is set
            
 Declaration Syntax
 Declaration Syntax| C# | 
public bool IsSetListSubscriptionsByTopicResult()
 Return Value
 Return Valuetrue if ListSubscriptionsByTopicResult property is set
 Declaration Syntax
 Declaration Syntax| C# | 
public bool IsSetListSubscriptionsByTopicResult()
 Return Value
 Return Value