code: public synchronized static void addFileHandler(String basename) throws IOException {
        String dir = Config.get("com.davidbracewell.logging.dir").asString(SystemInfo.USER_HOME + "/logs/");
        Resources.from(dir).mkdirs();
        FileHandler fh = new FileHandler(dir + "/" + basename + "%g.log", 100000000, 50, false);
        fh.setFormatter(new LogFormatter());
        addHandler(fh);
     }
docs: Adds a file handler that writes to the location specified in <code>com.davidbracewell.logging.dir</code> or if not
  set <code>USER_HOME/logs/</code>. The filenames are in the form of <code>basename%g</code> where %g is the rotated
  file number. Max file size is 100MB and 50 files will be used.