svc := autoscaling.New(session.New())

params := &autoscaling.SetInstanceHealthInput{
    HealthStatus:             aws.String("XmlStringMaxLen32"), // Required
    InstanceId:               aws.String("XmlStringMaxLen19"), // Required
    ShouldRespectGracePeriod: aws.Bool(true),
}
resp, err := svc.SetInstanceHealth(params)

if err != nil {
    // Print the error, cast err to awserr.Error to get the Code and
    // Message from an error.
    fmt.Println(err.Error())
    return
}

// Pretty-print the response data.
fmt.Println(resp)