def METHOD_NAME():
    root_dir = settings.get('corpora', 'colls_cache_dir')
    cache_ttl = settings.get_int('corpora', 'colls_cache_ttl', 3600)
    test_time = time.time()
    all_files = os.listdir(root_dir)
    num_removed = 0
    num_error = 0
    for item in all_files:
        file_path = os.path.join(root_dir, item)
        if test_time - os.path.getmtime(file_path) >= cache_ttl:
            try:
                os.unlink(file_path)
                num_removed += 1
            except OSError:
                num_error += 1
    return dict(total_files=len(all_files), num_removed=num_removed, num_error=num_error)