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.
          """
          headers, uri, bios_settings = self._check_bios_resource(['BootMode'])
          _, _, settings = self._get_bios_settings_resource(bios_settings)
          boot_mode = settings.get('BootMode')
          if boot_mode == 'LegacyBios':
              boot_mode = 'legacy'
          return boot_mode.upper()