ldap cache

http://freeradius.org/radiusd/doc/tuning_guide (also in the distro) LDAP MODULE o Enable caching in the ldap module ... I can find no such feature, does this actually exist in the ldap module or is there another way to cache ldap results? Did it used to exist? Ideally I'd like to be able to consult ldap but after a configured timeout simply use a cached result. Obviously I could do this with a script but why not have it all built-in. thanks.