code: func inNamespace(el *etree.Element, ns string) bool {
  	for _, attr := range el.Attr {
  		if attr.Value == ns {
  			if attr.Space == "" && attr.Key == "xmlns" {
  				return el.Space == ""
  			} else if attr.Space == "xmlns" {
  				return el.Space == attr.Key
  			}
  		}
  	}
  
  	return false
  }
docs: // TODO(russell_h): More flexible namespace support. This might barely work.