private static void usage() {
		System.out.println("Runs a tracker on provided address and port.\n");
		System.out.println("Usage: " +
				"tracker <-f filename> [-i ip] [-p port]");
		System.out.println("\tfilename\t-\tTorrent-file the tracker will track.");
		System.out.println("\tip\t\t-\tIP address or hostname to bind to. " +
				"Default: 'localhost'");
		System.out.println("\tport\t-\tPort to bind to. Default: " +
				"tracker's default port " + Tracker.DEFAULT_TRACKER_PORT);
	}