code: public Observable<ServiceResponse<Page<RouteFilterRuleInner>>> listByRouteFilterSinglePageAsync(final String resourceGroupName, final String routeFilterName) {
          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.");
          }
          final String apiVersion = "2018-07-01";
          return service.listByRouteFilter(resourceGroupName, routeFilterName, this.client.subscriptionId(), apiVersion, this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<Page<RouteFilterRuleInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<RouteFilterRuleInner>>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<PageImpl<RouteFilterRuleInner>> result = listByRouteFilterDelegate(response);
                          return Observable.just(new ServiceResponse<Page<RouteFilterRuleInner>>(result.body(), result.response()));
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Gets all RouteFilterRules in a route filter.
  
  ServiceResponse<PageImpl<RouteFilterRuleInner>> * @param resourceGroupName The name of the resource group.
  ServiceResponse<PageImpl<RouteFilterRuleInner>> * @param routeFilterName The name of the route filter.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the PagedList&lt;RouteFilterRuleInner&gt; object wrapped in {@link ServiceResponse} if successful.