type DelMarkerExpiration struct {
	XMLName xml.Name `xml:"DelMarkerExpiration"`
	Days    int      `xml:"Days,omitempty"`
}

// Empty returns if a DelMarkerExpiration XML element is empty.
// Used to detect if lifecycle.Rule contained a DelMarkerExpiration element.
func (de DelMarkerExpiration) Empty() bool {
	return de.Days == 0
}

// UnmarshalXML decodes a single XML element into a DelMarkerExpiration value