code: func Passes(token string) bool {
  	dec, err := newDecoded(token)
  	if err != nil {
  		// may want to log some error here so we have visibility
  		// intentionally simplifying return type to bool for ease
  		// of use in API. Caller should only do `if auth.Passes(str) {}`
  		return false
  	}
  	signed, err := dec.sign()
  	if err != nil {
  		return false
  	}
  
  	return signed.verify(encoded{token: token})
  }
docs: // Passes returns a bool indicating whether a token (string) provided has been signed by our server. If true, the client is authenticated and may proceed.