docs: public Observable<ExpressRouteGatewayInner> beginCreateOrUpdateAsync(String resourceGroupName, String expressRouteGatewayName, ExpressRouteGatewayInner putExpressRouteGatewayParameters) {
          return beginCreateOrUpdateWithServiceResponseAsync(resourceGroupName, expressRouteGatewayName, putExpressRouteGatewayParameters).map(new Func1<ServiceResponse<ExpressRouteGatewayInner>, ExpressRouteGatewayInner>() {
              @Override
              public ExpressRouteGatewayInner call(ServiceResponse<ExpressRouteGatewayInner> response) {
                  return response.body();
              }
          });
      }