@Test public void isStockServicesASingleton() { logger.info("Start isStockServicesASingleton ..."); SimpleStockServicesFactory factoryInstance = SimpleStockServicesFactory.INSTANCE; SimpleStockService simpleStockServiceA = factoryInstance.getSimpleStockService(); SimpleStockService simpleStockServiceB = factoryInstance.getSimpleStockService(); Assert.assertNotNull(simpleStockServiceA); Assert.assertNotNull(simpleStockServiceB); Assert.assertTrue(simpleStockServiceA.equals(simpleStockServiceB)); logger.info("Finish isStockServicesASingleton ...OK"); }