### Question:
WaarpLoggerFactory { public static void setDefaultFactory(final WaarpLoggerFactory factory) { if (factory == null) { throw new IllegalArgumentException("defaultFactory"); } WaarpLoggerFactory.defaultFactory = factory; if (factory instanceof WaarpJdkLoggerFactory) { InternalLoggerFactory.setDefaultFactory(JdkLoggerFactory.INSTANCE); } else if (factory instanceof WaarpSlf4JLoggerFactory) { InternalLoggerFactory.setDefaultFactory(Slf4JLoggerFactory.INSTANCE); } factory.seLevelSpecific(factory.getLevelSpecific()); } protected  WaarpLoggerFactory(final WaarpLogLevel level); static WaarpLoggerFactory getDefaultFactory(); static void setDefaultFactoryIfNotSame(
      final WaarpLoggerFactory factory); static void setDefaultFactory(final WaarpLoggerFactory factory); static WaarpLogger getInstance(final Class<?> clazz); static WaarpLogger getInstance(final String name); static WaarpLogger getLogger(final Class<?> clazz); static WaarpLogger getLogger(final String name); static void setLogLevel(final WaarpLogLevel level); static WaarpLogLevel getLogLevel(); static void setLocalName(final String localNameNew);  }### Answer:
@Test(expected = IllegalArgumentException.class) public void shouldNotAllowNullDefaultFactory() { WaarpLoggerFactory.setDefaultFactory(null); }