code: func NewProtector(input io.Reader) (ipnet.Protector, error) {
  	psk, err := decodeV1PSK(input)
  	if err != nil {
  		return nil, fmt.Errorf("malformed private network key: %s", err)
  	}
  	return NewV1ProtectorFromBytes(psk)
  }
docs: // NewProtector creates ipnet.Protector instance from a io.Reader stream
  // that should include Multicodec encoded V1 PSK.