code: private void println(int logLevel, String format, Object... args) {
      if (logLevel < logConfiguration.logLevel) {
        return;
      }
      printlnInternal(logLevel, formatArgs(format, args));
    }
docs: Print a log in a new line.
  
  @param logLevel the log level of the printing log
  @param format   the format of the printing log, null if just need to concat arguments
  @param args     the arguments of the printing log