code: public ServiceFuture<RouteFilterInner> getByResourceGroupAsync(String resourceGroupName, String routeFilterName, String expand, final ServiceCallback<RouteFilterInner> serviceCallback) {
          return ServiceFuture.fromResponse(getByResourceGroupWithServiceResponseAsync(resourceGroupName, routeFilterName, expand), serviceCallback);
      }
docs: Gets the specified route filter.
  
  @param resourceGroupName The name of the resource group.
  @param routeFilterName The name of the route filter.
  @param expand Expands referenced express route bgp peering resources.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object