func addChild(node *xmlx.Node, name string, attribs Attribs, contents string) *xmlx.Node {
child := xmlx.NewNode(xmlx.NT_ELEMENT)
child.Name.Local = name
child.Value = contents
for key, val := range attribs {
child.SetAttr(key, fmt.Sprintf("%v", val))
}
node.AddChild(child)
return child
}