Man pages matching name cache::memcached::fast in section 3pm:

Cache::Memcached::Fast.3pm.en	debian 10 / libcache-memcached-fast-perl
Cache::Memcached::Fast.3pm.en	debian 11 / libcache-memcached-fast-perl
Cache::Memcached::Fast.3pm.en	debian 12 / libcache-memcached-fast-perl