func main() {
	client := pagerduty.NewClient(authToken)
	svc, err := client.GetServiceWithContext(context.TODO(), serviceId, nil)
	if err != nil {
		panic(err)
	}

        // Whether there's no value from GetService or if it's set
	svc.AlertGroupingParameters.Type = ""

	_, err := client.UpdateServiceWithContext(context.TODO(), *svc)
	if err != nil {
                 // Results in panic: HTTP response failed with status code 400,
                 // message: Invalid Input Provided (code: 2001): Alert grouping parameters is invalid.
		panic(err)
	}
}