* @return the number of files purged
     */
    public long purge(final long expiry) {
        if (!baseDir.exists()) {
            return 0;
        }
        try {
            final FilePurgeVisitor visitor = new FilePurgeVisitor(baseDir.toPath(), imageExtention, expiry);
            Files.walkFileTree(baseDir.toPath(), visitor);
            return visitor.getCount();
        } catch (final Exception e) {