Parses the XML element as a group of [unknown] number of lines.

def _group(self, element):
        """Parses the XML element as a group of [unknown] number of lines."""
        for v in _get_xml_version(element):
            if "name" in element.attrib:
                g = TemplateGroup(element, self.versions[v].comment)
                self.versions[v].entries[g.identifier] = g
                self.versions[v].order.append(g.identifier)
            else:
                msg.warn("no name element in {}. Ignored. (_group)".format(element))