code: protected void initialize(ConfigurableEnvironment environment,
  			ClassLoader classLoader) {
  		new LoggingSystemProperties(environment).apply();
  		LogFile logFile = LogFile.get(environment);
  		if (logFile != null) {
  			logFile.applyToSystemProperties();
  		}
  		initializeEarlyLoggingLevel(environment);
  		initializeSystem(environment, this.loggingSystem, logFile);
  		initializeFinalLoggingLevels(environment, this.loggingSystem);
  		registerShutdownHookIfNecessary(environment, this.loggingSystem);
  	}
docs: Initialize the logging system according to preferences expressed through the
  {@link Environment} and the classpath.
  @param environment the environment
  @param classLoader the classloader