Frontend LDAP Error code improvement

public function getError() {
                $error = parent::getError();
                $messages = [
                        CLdap::ERR_PHP_EXTENSION => _('PHP LDAP extension missing.'),
                        CLdap::ERR_SERVER_UNAVAILABLE => _('Cannot connect to LDAP server.'),
                        CLdap::ERR_BIND_FAILED => _('Cannot bind to LDAP server.'),
                        CLdap::ERR_BIND_ANON_FAILED => _('Cannot bind anonymously to LDAP server.'),
                        CLdap::ERR_USER_NOT_FOUND => _('Login name or password is incorrect.'),
                        CLdap::ERR_OPT_PROTOCOL_FAILED => _('Setting LDAP protocol failed.'),
                        CLdap::ERR_OPT_TLS_FAILED => _('Starting TLS failed.'),
                        CLdap::ERR_OPT_REFERRALS_FAILED => _('Setting LDAP referrals to "Off" failed.'),
                        CLdap::ERR_OPT_DEREF_FAILED => _('Setting LDAP dereferencing mode failed.')
             ];