code: func NewMemoryWithTTL(ttl time.Duration) *MemoryTTL {
  	return &MemoryTTL{
  		cache:  NewMemoryNoTS(),
  		setAts: map[string]time.Time{},
  		ttl:    ttl,
  	}
  }
docs: // NewMemoryWithTTL creates an inmemory cache system
  // Which everytime will return the true values about a cache hit
  // and never will leak memory
  // ttl is used for expiration of a key from cache