type Config struct {
	XMLNS      string   `xml:"xmlns,attr,omitempty"`
	XMLName    xml.Name `xml:"NotificationConfiguration"`
	QueueList  []Queue  `xml:"QueueConfiguration,omitempty"`
	LambdaList []lambda `xml:"CloudFunctionConfiguration,omitempty"`
	TopicList  []topic  `xml:"TopicConfiguration,omitempty"`
}

// UnmarshalXML - decodes XML data.