code: def _line(self, element):
          
          for v in _get_xml_version(element):
              if "id" in element.attrib:
                  tline = TemplateLine(element, None, self.versions[v].comment)
                  self.versions[v].entries[tline.identifier] = tline
                  self.versions[v].order.append(tline.identifier)
              else:
                  msg.warn("no id element in {}. Ignored. (_line)".format(element))
docs: Parses the XML element as a single line entry in the input file.