docs: def _load_permissions(campus, calendarid, resp_fragment, permission_list):
      """
      :return: a list of sorted trumba.Permission objects
               None if error, [] if not exists
      """
      for record in resp_fragment:
          if not _is_valid_email(record['Email']):
              # skip the non UW users
              continue
          perm = Permission()
          perm.calendarid = calendarid
          perm.campus = campus
          perm.uwnetid = _extract_uwnetid(record['Email'])
          perm.level = record['Level']
          perm.name = str(record['Name'])
          permission_list.append(perm)