func MustParseXML(r io.Reader, op ...ParseSettings) tree.Node {
	ret, err := ParseXML(r, op...)

	if err != nil {
		panic(err)
	}

	return ret
}
func MustParseXML(r io.Reader, op ...ParseSettings) tree.Node {
	ret, err := ParseXML(r, op...)

	if err != nil {
		panic(err)
	}

	return ret
}
//MustParseXML is like ParseXML, but panics instead of returning an error.