code: package org.rug.simpletests;
  
  import org.apache.log4j.Level;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.junit.jupiter.api.Test;
  
  
  public class LoggerTest {
  
      private static Logger logger = LogManager.getLogger(Logger.class);
  
      @Test
      void testLoggers(){
          org.apache.log4j.Logger.getRootLogger().setLevel(Level.ALL);
          logger.error("Error message.");
          logger.debug("Debug message.");
          logger.info("Info message.");
          logger.warn("Warning message.");
          logger.fatal("Fatal message.");
      }
  }
  