code: def _decode_subelements(self):
          
          for child in self._element:
              if child.tag == self._subject_tag:
                  self._subject = child.text
              elif child.tag == self._body_tag:
                  self._body = child.text
              elif child.tag == self._thread_tag:
                  self._thread = child.text
docs: Decode the stanza subelements.