code: def get_group_names(self):
          
          if self._group_names is None:
              self._load_cached_attr("_group_names")
  
          if self._group_names is None:
              group_infos = self._get_group_infos()
              self._group_names = {
                  self._group_type.group_name_from_info(group_info)
                  for group_info in group_infos
              }
              self._cache_attr("_group_names")
  
          return self._group_names
docs: Returns the set of Django group names that this user belongs to by
          virtue of LDAP group memberships.