code: public Observable<ServiceResponse<IntegrationAccountInner>> regenerateAccessKeyWithServiceResponseAsync(String resourceGroupName, String integrationAccountName) {
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (integrationAccountName == null) {
              throw new IllegalArgumentException("Parameter integrationAccountName is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          final KeyType keyType = null;
          RegenerateActionParameter regenerateAccessKey = new RegenerateActionParameter();
          regenerateAccessKey.withKeyType(null);
          return service.regenerateAccessKey(this.client.subscriptionId(), resourceGroupName, integrationAccountName, this.client.apiVersion(), this.client.acceptLanguage(), regenerateAccessKey, this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<IntegrationAccountInner>>>() {
                  @Override
                  public Observable<ServiceResponse<IntegrationAccountInner>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<IntegrationAccountInner> clientResponse = regenerateAccessKeyDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Regenerates the integration account access key.
  
  @param resourceGroupName The resource group name.
  @param integrationAccountName The integration account name.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the IntegrationAccountInner object