code: func (n NamespacedKV) String(key string) (string, bool) {
  	valBs, err := n.db.Get(n.prefixedKey(key), nil)
  	if err != nil {
  		return "", false
  	}
  	return string(valBs), true
  }
docs: // String returns the stored value interpreted as a string and a boolean that
  // is false if no value was stored at the key.