* The value is, e.g. true <br>
     * comment: Whether to get FTP roles from a file.
     * @return The determination, true or false. (if not found, exception but basically no way)
     */
    boolean isFtpRoleFromFile();

    /**
     * Get the value for the key 'index.backup.targets'. <br>
     * The value is, e.g. fess_basic_config.bulk,fess_config.bulk,fess_user.bulk,system.properties,fess.json,doc.json <br>