code: def get_xml(self):
          
          if not self._dirty:
              return self._element
          element = self.as_xml()
          self._element = element
          self._dirty = False
          return element
docs: Return the XML stanza representation.
  
          This returns the original or cached XML representation, which
          may be much more efficient than `as_xml`.
  
          Result of this function should never be modified.
  
          :returntype: :etree:`ElementTree.Element`