AbstractLoggerFactory implements LoggerFactory { @Override public synchronized void setFormatter(LoggerFormatter formatter) { this.formatter = Objects.requireNonNull(formatter); forEachLogger(l -> l.setFormatter(formatter)); } AbstractLoggerFactory(); @Override Logger create(Class<?> binding); @Override Logger create(String binding); @Override synchronized void setFormatter(LoggerFormatter formatter); @Override synchronized LoggerFormatter getFormatter(); abstract Logger make(String binding, LoggerFormatter formatter); @Override void addListener(LoggerEventListener listener); @Override void removeListener(LoggerEventListener listener); @Override Stream<LoggerEventListener> listeners(); @Override Stream<Entry<String, Logger>> loggers(); @Override void setLevel(String path, Level level); @Override void setLevel(Class<?> binding, Level level);  }
@Test void setFormatter() { instance.setFormatter(FORMATTER); assertEquals(FORMATTER, instance.getFormatter()); final Logger logger = instance.create("SetFormatterBinding"); logger.fatal("A"); assertTrue(output.contains(FORMATTER_TEXT)); }