code: def _format_attrs(self):
          
          attrs = [
              ('levels', ibase.default_pprint(self._levels,
                                              max_seq_items=False)),
              ('codes', ibase.default_pprint(self._codes,
                                             max_seq_items=False))]
          if com._any_not_none(*self.names):
              attrs.append(('names', ibase.default_pprint(self.names)))
          if self.sortorder is not None:
              attrs.append(('sortorder', ibase.default_pprint(self.sortorder)))
          return attrs
docs: Return a list of tuples of the (attr,formatted_value)