code: public Observable<SubscriptionQuotasListResultInner> listQuotasAsync(String location) {
          return listQuotasWithServiceResponseAsync(location).map(new Func1<ServiceResponse<SubscriptionQuotasListResultInner>, SubscriptionQuotasListResultInner>() {
              @Override
              public SubscriptionQuotasListResultInner call(ServiceResponse<SubscriptionQuotasListResultInner> response) {
                  return response.body();
              }
          });
      }
docs: Retrieves the subscription's current quota information in a particular region.
  
  @param location The region in which to retrieve the subscription's quota information. You can find out which regions Azure Stream Analytics is supported in here: https://azure.microsoft.com/en-us/regions/
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the SubscriptionQuotasListResultInner object