def METHOD_NAME():
    parser = OptionParser(
        version="naturalselection v0.3",
        description="Cache directory manager. Deletes cache entries based on accesstime and free space thresholds.\n" +
            "This utility is distributed alongside SabreDAV.",
        usage="usage: %prog [options] cacheDirectory",
    )
    parser.add_option(
        '-s',
        dest="simulate",
        action="store_true",
        help="Don't actually make changes, but just simulate the behaviour",
    )
    parser.add_option(
        '-r','--runs',
        help="How many times to check before exiting. -1 is infinite, which is the default",
        type="int",
        dest="runs",
        default=-1
    )
    parser.add_option(
        '-n','--interval',
        help="Sleep time in seconds (default = 5)",
        type="int",
        dest="sleep",
        default=5
    )
    parser.add_option(
        '-l','--threshold',
        help="Threshold in bytes (default = 10737418240, which is 10GB)",
        type="int",
        dest="threshold",
        default=10737418240
    )
    parser.add_option(
        '-m', '--min-erase',
        help="Minimum number of bytes to erase when the threshold is reached. " +
            "Setting this option higher will reduce the number of times the cache directory will need to be scanned. " +
            "(the default is 1073741824, which is 1GB.)",
        type="int",
        dest="min_erase",
        default=1073741824
    )
    options,args = parser.parse_args()
    if len(args)<1:
        parser.error("This utility requires at least 1 argument")
    cacheDir = args[0]
    print "Natural Selection"
    print "Cache directory:", cacheDir
    free = getfreespace(cacheDir);
    print "Current free disk space:", free
    runs = options.runs;
    while runs!=0 :
        run(
            cacheDir,
            sleep=options.sleep,
            simulate=options.simulate,
            threshold=options.threshold,
            min_erase=options.min_erase
        )
        if runs>0:
            runs = runs - 1