logger.warn("Failed to generate a thumbnail of {}: {}", thumbnailId, commandList, e);
        }
        if (task != null && !task.isExecuted()) {
            task.cancel();
        }
    }

    protected static class ProcessDestroyer extends TimerTask {

        private final Process p;

        private final InputStreamThread ist;

        private final AtomicBoolean executed = new AtomicBoolean(false);