code: func JWTTokenAuthenticator(iss string, keys []interface{}, implicitAuds authenticator.Audiences, validator Validator) authenticator.Token {
  	return &jwtTokenAuthenticator{
  		iss:          iss,
  		keys:         keys,
  		implicitAuds: implicitAuds,
  		validator:    validator,
  	}
  }
docs: // JWTTokenAuthenticator authenticates tokens as JWT tokens produced by JWTTokenGenerator
  // Token signatures are verified using each of the given public keys until one works (allowing key rotation)
  // If lookup is true, the service account and secret referenced as claims inside the token are retrieved and verified with the provided ServiceAccountTokenGetter