func (s *SessionCache) getInvalidTokenError(token string) error {
	return errors.New(fmt.Sprintf(
		"The requested token '%s' is invalid or is expired", token))
}
func (s *SessionCache) getInvalidTokenError(token string) error {
	return errors.New(fmt.Sprintf(
		"The requested token '%s' is invalid or is expired", token))
}
// getInvalidTokenError gets the default error when an invalid or expired token
// is requested.