code: func SplitMetaNamespaceKey(key string) (namespace, name string, err error) {
  	parts := strings.Split(key, "/")
  	switch len(parts) {
  	case 1:
  		// name only, no namespace
  		return "", parts[0], nil
  	case 2:
  		// namespace and name
  		return parts[0], parts[1], nil
  	}
  
  	return "", "", fmt.Errorf("unexpected key format: %q", key)
  }
docs: // SplitMetaNamespaceKey returns the namespace and name that
  // MetaNamespaceKeyFunc encoded into key.
  //
  // TODO: replace key-as-string with a key-as-struct so that this
  // packing/unpacking won't be necessary.