in log4j-api-to-jul/src/main/java/org/apache/logging/log4j/tojul/JULLoggerContext.java [74:78]
public boolean hasLogger(final String name, final MessageFactory messageFactory) {
final MessageFactory effectiveMessageFactory =
messageFactory != null ? messageFactory : DEFAULT_MESSAGE_FACTORY;
return loggerRegistry.hasLogger(name, effectiveMessageFactory);
}