code: @FormatMethod
    public void log(String format, @Nullable Object... args) {
      if (enabled) {
        System.out.print(getIndentString());
        System.out.printf(format, args);
      }
    }
docs: Log a message to System.out. The message is prepended with the current indentation string. The
  indentation is only applied at the start of the message, not for every line break within the
  message.
  
  @param format format string for message
  @param args values to be substituted into format