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