code: func NewMemoryStore() Store {
  	return &memoryStore{
  		cache: make(map[string]*entry.Entry),
  		mu:    sync.RWMutex{},
  	}
  }
docs: // NewMemoryStore returns a new memory store for the cache ,
  // note that httpcache package provides one global default cache service  which provides these functions:
  // `httpcache.Cache`, `httpcache.Invalidate` and `httpcache.Start`
  //
  // If you use only one global cache for all of your routes use the `httpcache.New` instead