def begin_create_or_update(resource_group_name, express_route_gateway_name, put_express_route_gateway_parameters, custom_headers:nil)
      response = begin_create_or_update_async(resource_group_name, express_route_gateway_name, put_express_route_gateway_parameters, custom_headers:custom_headers).value!
      response.body unless response.nil?
    end
def begin_create_or_update(resource_group_name, express_route_gateway_name, put_express_route_gateway_parameters, custom_headers:nil)
      response = begin_create_or_update_async(resource_group_name, express_route_gateway_name, put_express_route_gateway_parameters, custom_headers:custom_headers).value!
      response.body unless response.nil?
    end
Creates or updates a ExpressRoute gateway in a specified resource group.

 @param resource_group_name [String] The name of the resource group.
 @param express_route_gateway_name [String] The name of the ExpressRoute
 gateway.
 @param put_express_route_gateway_parameters [ExpressRouteGateway] Parameters
 required in an ExpressRoute gateway PUT operation.
 @param custom_headers [Hash{String => String}] A hash of custom headers that
 will be added to the HTTP request.

 @return [ExpressRouteGateway] operation results.