How configure client-class for pools in db?

For correct working HA it need to configure client-class for each pool as in documentaion:

"pools": [
    {
       "pool": "192.0.3.100 - 192.0.3.150",
       "client-class": "HA_server1"
    },
    {
       "pool": "192.0.3.200 - 192.0.3.250",
       "client-class": "HA_server2"
    }
],

But DB scheme (tables dhcp4_pool and dhcp6_pool) has not column for client-class:

CREATE TABLE `dhcp4_pool` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `start_address` int(10) unsigned NOT NULL,
  `end_address` int(10) unsigned NOT NULL,
  `subnet_id` int(10) unsigned NOT NULL,
  `modification_ts` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `key_dhcp4_pool_modification_ts` (`modification_ts`),
  KEY `fk_dhcp4_pool_subnet_id` (`subnet_id`),
  CONSTRAINT `fk_dhcp4_pool_subnet_id` FOREIGN KEY (`subnet_id`) REFERENCES `dhcp4_subnet` (`subnet_id`) ON DELETE CASCADE ON UPDATE CASCADE
)