if( !name.endsWith( ".zip" ) ) {
throw( new XPathException( this, "for security reasons, the function only allows " + "reading zipped backup archives" ) );
}
try {
final ZipArchiveBackupDescriptor descriptor = new ZipArchiveBackupDescriptor( backupFile );
final Properties properties = descriptor.getProperties();
if( ( properties == null ) || ( properties.size() == 0 ) ) {
throw( new XPathException( this, "the file does not see to be a valid backup archive" ) );
}
}