docs: def get_pending_boot_mode(self):
          """Retrieves the pending boot mode of the server.
  
          Gets the boot mode to be set on next reset.
          :returns: either LEGACY or UEFI.
          :raises: IloError, on an error from iLO.
          """
          sushy_system = self._get_sushy_system(PROLIANT_SYSTEM_ID)
          try:
              return BOOT_MODE_MAP.get(
                  sushy_system.bios_settings.pending_settings.boot_mode)
          except sushy.exceptions.SushyError as e:
              msg = (self._('The pending BIOS Settings was not found. Error '
                            '%(error)s') %
                     {'error': str(e)})
              LOG.debug(msg)
              raise exception.IloError(msg)