code: public Observable<ServiceResponse<RouteFilterInner>> createOrUpdateWithServiceResponseAsync(String resourceGroupName, String routeFilterName, RouteFilterInner routeFilterParameters) {
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (routeFilterName == null) {
              throw new IllegalArgumentException("Parameter routeFilterName 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 (routeFilterParameters == null) {
              throw new IllegalArgumentException("Parameter routeFilterParameters is required and cannot be null.");
          }
          Validator.validate(routeFilterParameters);
          final String apiVersion = "2018-08-01";
          Observable<Response<ResponseBody>> observable = service.createOrUpdate(resourceGroupName, routeFilterName, this.client.subscriptionId(), routeFilterParameters, apiVersion, this.client.acceptLanguage(), this.client.userAgent());
          return client.getAzureClient().getPutOrPatchResultAsync(observable, new TypeToken<RouteFilterInner>() { }.getType());
      }
docs: Creates or updates a route filter in a specified resource group.
  
  @param resourceGroupName The name of the resource group.
  @param routeFilterName The name of the route filter.
  @param routeFilterParameters Parameters supplied to the create or update route filter operation.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request