LogHelper { public static void info(Logger logger, String msg) { if (logger == null) { return; } if (logger.isInfoEnabled()) { logger.info(msg); } } private  LogHelper(); static void trace(Logger logger, String msg); static void trace(Logger logger, Throwable throwable); static void trace(Logger logger, String msg, Throwable e); static void debug(Logger logger, String msg); static void debug(Logger logger, Throwable e); static void debug(Logger logger, String msg, Throwable e); static void info(Logger logger, String msg); static void info(Logger logger, Throwable e); static void info(Logger logger, String msg, Throwable e); static void warn(Logger logger, String msg, Throwable e); static void warn(Logger logger, String msg); static void warn(Logger logger, Throwable e); static void error(Logger logger, Throwable e); static void error(Logger logger, String msg); static void error(Logger logger, String msg, Throwable e);  }
@Test public void testInfo() throws Exception { Logger logger = Mockito.mock(Logger.class); when(logger.isInfoEnabled()).thenReturn(true); LogHelper.info(logger, "info"); verify(logger).info("info"); Throwable t = new RuntimeException(); LogHelper.info(logger, t); verify(logger).info(t); LogHelper.info(logger, "info", t); verify(logger).info("info", t); }