code: public static int w(String tag, String msg) {
          return w(SUBSYSTEM.MAIN, tag, msg);
      }
docs: Send a WARN log message with {@link SUBSYSTEM#MAIN} as default one .
  @param tag Used to identify the source of a log message. It usually identifies the class or
  activity where the log call occurs.
  @param msg The message you would like logged.
  @return