return convertEmptyToNull(surname);
    }

    public void setSurname(String value) {
        registerModifiedProperty("surname");
        this.surname = value;
    }

    public String getTelephoneNumber() {
        checkSpecifiedProperty("telephoneNumber");
        return convertEmptyToNull(telephoneNumber);
    }

    public void setTelephoneNumber(String value) {

        setupEpg(_epgMap, et -> ((User) et).getSurname(), (et, vl) -> ((User) et).setSurname(DfTypeUtil.toString(vl)), "surname");
        setupEpg(_epgMap, et -> ((User) et).getTelephoneNumber(), (et, vl) -> ((User) et).setTelephoneNumber(DfTypeUtil.toString(vl)),
                "telephoneNumber");
        setupEpg(_epgMap, et -> ((User) et).getTeletexTerminalIdentifier(),

                        .forEach(v -> modifyDeleteEntry(modifyList, attrEmployeeNumber, v)));
        final String attrTelephoneNumber = fessConfig.getLdapAttrTelephoneNumber();
        OptionalUtil.ofNullable(user.getTelephoneNumber()).filter(StringUtil::isNotBlank)
                .ifPresent(s -> modifyReplaceEntry(modifyList, attrTelephoneNumber, s))
                .orElse(() -> getAttributeValueList(result, attrTelephoneNumber).stream()