code: function onReferralError(err) {
              log.error(err, '[%s] An error occurred chasing the LDAP referral on %s (%j)',
                       (err || {}).errno, referralBaseDn, opts);
              removeReferral(referralClient);
            }
docs: Occurs when a error is encountered with the referral client.
  @param {Object} err The error object or string.