func (receiver Device) MustCard() string {
	datum, err := receiver.Card()
	if nil != err {
		panic(err)
	}
	return datum
}
MustCard is like BusCard, except it panic()s if there is an error.

device := v4l2.MustOpen(v4l2.Video0)
defer device.MustClose()

fmt.Printf("Card: %q \n", device.MustCard())
package v4l2
func (receiver Device) Card() (string, error) {
	if err := receiver.unfit(); nil != err {
		return "", err
	}
	return receiver.cap.Card(), nil
}