code: public void doPost(final LoggingEvent event) {
          // if event does not meet threshold, exit now
          if (!isAsSevereAsThreshold(event.getLevel())) {
              return;
          }
  
          // get the "local" logger for this event from the
          // configured repository.
          Logger localLogger =
                  getLoggerRepository().getLogger(event.getLoggerName());
  
          // if the logger level is greater or equal to the level
          // of the event, use the logger to append the event.
          if (event.getLevel()
                  .isGreaterOrEqual(localLogger.getEffectiveLevel())) {
              // call the loggers appenders to process the event
              localLogger.callAppenders(event);
          }
    }
docs: Posts the logging event to a logger in the configured logger
  repository.
  
  @param event the log event to post to the local log4j environment.