docs: def parse_xml_node(self, node):
          '''Parse an xml.dom Node object representing a participant into this
          object.
  
          '''
          if node.getElementsByTagNameNS(RTS_NS, 'Participant').length != 1:
              raise InvalidParticipantNodeError
          self.target_component = TargetComponent().parse_xml_node(\
                  node.getElementsByTagNameNS(RTS_NS, 'Participant')[0])
          return self