code: func DecodeUnverifiedToken(buf []byte, ut *UnverifiedToken) error {
  	b := bytes.Split(buf, tokenSep)
  	if len(b) != 3 {
  		return ErrInvalidToken
  	}
  
  	ut.Header = b[0]
  	ut.Payload = b[1]
  	ut.Signature = b[2]
  
  	return nil
  }
docs: // DecodeUnverifiedToken decodes a token into the provided UnverifiedToken.