code: public ServiceFuture<List<EventSubscriptionInner>> listRegionalBySubscriptionForTopicTypeAsync(String location, String topicTypeName, final ServiceCallback<List<EventSubscriptionInner>> serviceCallback) {
          return ServiceFuture.fromResponse(listRegionalBySubscriptionForTopicTypeWithServiceResponseAsync(location, topicTypeName), serviceCallback);
      }
docs: List all regional event subscriptions under an Azure subscription for a topic type.
  List all event subscriptions from the given location under a specific Azure subscription and topic type.
  
  @param location Name of the location
  @param topicTypeName Name of the topic type
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object