code: public static void openLogFile(String logPath) {
  		if (logPath == null) {
  			printStream = System.out;
  		} else {
  			try {
  				printStream = new PrintStream(new File(logPath));
  			} catch (FileNotFoundException e) {
  				throw new IllegalArgumentException("Log file " + logPath + " was not found", e);
  			}
  		}
  	}
docs: Reopen the associated static logging stream. Set to null to redirect to System.out.