@Before
  public void setUp() {
    enabledMarker = MarkerManager.getMarker(ENABLED_MARKER_NAME);
    unusedMarker = MarkerManager.getMarker(UNUSED_MARKER_NAME);

    logger = LogService.getLogger(TEST_LOGGER_NAME);

    assertThat(LogService.getLogger(MAIN_LOGGER_NAME).getLevel()).isEqualTo(Level.FATAL);
    assertThat(logger).isInstanceOf(FastLogger.class);
    assertThat(logger.getLevel()).isEqualTo(Level.WARN);

    LogConfig logConfig = mock(LogConfig.class);
    when(logConfig.getLogLevel()).thenReturn(CONFIG.intLevel());
    when(logConfig.getSecurityLogLevel()).thenReturn(CONFIG.intLevel());

    LogConfigSupplier logConfigSupplier = mock(LogConfigSupplier.class);
    when(logConfigSupplier.getLogConfig()).thenReturn(logConfig);

    configuration = create(LogLevelUpdateOccurs.NEVER, LogLevelUpdateScope.GEODE_LOGGERS);
    configuration.initialize(logConfigSupplier);
  }
This config file is generated dynamically by the test class.
geode-log4j/src/integrationTest/java/org/apache/geode/logging/log4j/internal/impl/FastLoggerIntegrationTest.java