Man pages matching name memcached_stat_get_keys in section 3:

memcached_stat_get_keys.3.en	debian 10 / libmemcached-dev
memcached_stat_get_keys.3.en	debian 11 / libmemcached-dev
memcached_stat_get_keys.3.en	debian 12 / libmemcached-dev