return value != null ? DfTypeUtil.toLong(value) : null;
    }

    String getPasswordInvalidAdminPasswords();

    default boolean isValidAdminPassword(final String password) {
        return !split(getPasswordInvalidAdminPasswords(), "\n")
                .get(stream -> stream.map(String::trim).filter(StringUtil::isNotEmpty).anyMatch(s -> s.equals(password)));
    }

     * The value is, e.g. admin <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getPasswordInvalidAdminPasswords();

    /**
     * The simple implementation for configuration.
     * @author FreeGen
     */
    public static class SimpleImpl extends FessEnv.SimpleImpl implements FessConfig {