sharded.go
func (sc *shardedCache) Items() []map[string]Item {
	res := make([]map[string]Item, len(sc.cs))
	for i, v := range sc.cs {
		res[i] = v.Items()
	}
	return res
}
func (sc *shardedCache) Items() []map[string]Item {
	res := make([]map[string]Item, len(sc.cs))
	for i, v := range sc.cs {
		res[i] = v.Items()
	}
	return res
}
// Returns the items in the cache. This may include items that have expired,
// but have not yet been cleaned up. If this is significant, the Expiration
// fields of the items should be checked. Note that explicit synchronization
// is needed to use a cache and its corresponding Items() return values at
// the same time, as the maps are shared.