protected static function writeUpdateToken( $tokenFile, $tokenLine )
    {
        $sys = eZSys::instance();
        $updateViewLogPath = $sys->varDirectory() . "/" . eZPerfLoggerINI::variable( 'FileSettings', 'LogDir', 'site.ini' ) . "/" . $tokenFile;
        $dt = new eZDateTime();
        if ( !file_put_contents(
            $updateViewLogPath,
            "# Finished at " . $dt->toString() . "\n" .
            "# Last updated entry:" . "\n" .
            $tokenLine . "\n" ) )
        {
            eZPerfLoggerDebug::writeError( "Could not store last date of perf-log file parsing in $updateViewLogPath, double-counting might occur", __METHOD__ );
        }
    }