### Question:
MessageBus implements IOFogModule { public synchronized String getNextId() { return idGenerator.getNextId(); } private  MessageBus(); @Override int getModuleIndex(); @Override String getModuleName(); static MessageBus getInstance(); synchronized void enableRealTimeReceiving(String receiver); synchronized void disableRealTimeReceiving(String receiver); void update(); void instanceConfigUpdated(); void startServer(); void start(); void stop(); MessagePublisher getPublisher(String publisher); MessageReceiver getReceiver(String receiver); synchronized String getNextId(); synchronized Map<String, Route> getRoutes();  }### Answer:
@Test public void testGetNextId() { initiateMockStart(); assertNotNull(messageBus.getNextId()); }