}

    // Test FilePurgeVisitor
    public void test_FilePurgeVisitor() throws IOException {
        // Create a test file
        File testFile = new File(tempDir, "_1/_2/test.png");
        testFile.getParentFile().mkdirs();
        testFile.createNewFile();
        testFile.setLastModified(System.currentTimeMillis() - 2000L);

        // Since FilePurgeVisitor is an inner class and we can't directly test it,

     * @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) {