code: public static void init(int logLevel, Printer... printers) {
      init(new LogConfiguration.Builder().logLevel(logLevel).build(), printers);
    }
docs: Initialize log system, should be called only once.
  
  @param logLevel the log level, logs with a lower level than which would not be printed
  @param printers the printers, each log would be printed by all of the printers