code: func NewFrom(defaultExpiration, cleanupInterval time.Duration, items map[string]Item) *Cache {
  	return newCacheWithJanitor(defaultExpiration, cleanupInterval, items)
  }
docs: // Return a new cache with a given default expiration duration and cleanup
  // interval. If the expiration duration is less than one (or NoExpiration),
  // the items in the cache never expire (by default), and must be deleted
  // manually. If the cleanup interval is less than one, expired items are not
  // deleted from the cache before calling c.DeleteExpired().
  //
  // NewFrom() also accepts an items map which will serve as the underlying map
  // for the cache. This is useful for starting from a deserialized cache
  // (serialized using e.g. gob.Encode() on c.Items()), or passing in e.g.
  // make(map[string]Item, 500) to improve startup performance when the cache
  // is expected to reach a certain minimum size.
  //
  // Only the cache's methods synchronize access to this map, so it is not
  // recommended to keep any references to the map around after creating a cache.
  // If need be, the map can be accessed at a later point using c.Items() (subject
  // to the same caveat.)
  //
  // Note regarding serialization: When using e.g. gob, make sure to
  // gob.Register() the individual types stored in the cache before encoding a
  // map retrieved with c.Items(), and to register those same types before
  // decoding a blob containing an items map.