code: public Observable<ServiceResponse<CognitiveServicesAccountKeysInner>> listKeysWithServiceResponseAsync(String resourceGroupName, String accountName) {
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (accountName == null) {
              throw new IllegalArgumentException("Parameter accountName 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.listKeys(resourceGroupName, accountName, this.client.subscriptionId(), this.client.apiVersion(), this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<CognitiveServicesAccountKeysInner>>>() {
                  @Override
                  public Observable<ServiceResponse<CognitiveServicesAccountKeysInner>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<CognitiveServicesAccountKeysInner> clientResponse = listKeysDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Lists the account keys for the specified Cognitive Services account.
  
  @param resourceGroupName The name of the resource group within the user's subscription.
  @param accountName The name of Cognitive Services account.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the CognitiveServicesAccountKeysInner object