func NewCache(d time.Duration) *Cache {
	return &Cache{
		values:   make(map[string]*cacheItem),
		lifetime: d,
	}
}
func NewCache(d time.Duration) *Cache {
	return &Cache{
		values:   make(map[string]*cacheItem),
		lifetime: d,
	}
}
func NewCache ( d time . Duration ) * Cache { return & Cache { values : make ( map [ string ] * cacheItem ) , lifetime : d , } }
// NewCache creates a new instance of Cache and defines the default lifetime for
// new cached items.
NewCache creates a new instance of Cache and defines the default lifetime for new cached items .