### Question:
BrokerStartup { private static void properties2SystemEnv(Properties properties) { if (properties == null) { return; } String rmqAddressServerDomain = properties.getProperty("rmqAddressServerDomain", MixAll.WS_DOMAIN_NAME); String rmqAddressServerSubGroup = properties.getProperty("rmqAddressServerSubGroup", MixAll.WS_DOMAIN_SUBGROUP); System.setProperty("rocketmq.namesrv.domain", rmqAddressServerDomain); System.setProperty("rocketmq.namesrv.domain.subgroup", rmqAddressServerSubGroup); }  static void main(String[] args); static BrokerController start(BrokerController controller); static BrokerController createBrokerController(String[] args); static Properties properties; static CommandLine commandLine; static String configFile; static Logger log; }### Answer:
@Test public void testProperties2SystemEnv() throws NoSuchMethodException, InvocationTargetException, IllegalAccessException { Properties properties = new Properties(); Class<BrokerStartup> clazz = BrokerStartup.class; Method method = clazz.getDeclaredMethod("properties2SystemEnv", Properties.class); method.setAccessible(true); System.setProperty("rocketmq.namesrv.domain", "value"); method.invoke(null, properties); Assert.assertEquals("value", System.getProperty("rocketmq.namesrv.domain")); }