void deleteObsoleteFiles() {
		final long rrdDiskUsage = CounterStorage.deleteObsoleteCounterFiles(getApplication());
		final long serGzDiskUsage = JRobin.deleteObsoleteJRobinFiles(getApplication());
		diskUsage = rrdDiskUsage + serGzDiskUsage;
		// il manque la taille du fichier "last_shutdown.html", mais on n'est pas à ça près
		LOG.debug("Obsolete files deleted. JavaMelody disk usage: " + diskUsage / 1024 + " KB");
	}
@Test
	public void testDeleteObsoleteFiles() {
		final Collector collector = createCollectorWithOneCounter();
		collector.deleteObsoleteFiles();
	}