code: public Observable<ServiceResponse<SubscriptionQuotasListResultInner>> listQuotasWithServiceResponseAsync(String location) {
          if (location == null) {
              throw new IllegalArgumentException("Parameter location is required and cannot be null.");
          }
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          return service.listQuotas(location, this.client.subscriptionId(), this.client.apiVersion(), this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<SubscriptionQuotasListResultInner>>>() {
                  @Override
                  public Observable<ServiceResponse<SubscriptionQuotasListResultInner>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<SubscriptionQuotasListResultInner> clientResponse = listQuotasDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
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