cb := func(k string, v interface{}) {
fmt.Printf("key: %s | value: %+v\n", k, v)
}
cache := niftycache.New(10*time.Minute,
niftycache.ExpireCallback(cb),
niftycache.RemoveCallback(cb),
niftycache.SetCallback(cb),
// controls whether a successful cache hit extends the item's ttl (default false)
niftycache.ExtendTTLOnHit(),
// controls the max amount of items that can be expired at once (default 10000)
niftycache.MaxExpires(10000),
// controls the max amount of concurrent callbacks that can be fired (default 1000)
niftycache.MaxCallbacks(1000),
)