code: func (db ErroringDB) IsAllowedOAuthClientID(c context.Context, email, clientID string) (bool, error) {
  	logging.Errorf(c, "%s", db.Error)
  	return false, db.Error
  }
docs: // IsAllowedOAuthClientID returns true if given OAuth2 client_id can be used
  // to authenticate access for given email.