### Question:
FieldAgent implements IOFogModule { public static FieldAgent getInstance() { if (instance == null) { synchronized (FieldAgent.class) { if (instance == null) instance = new FieldAgent(); } } return instance; } private  FieldAgent(); @Override int getModuleIndex(); @Override String getModuleName(); static FieldAgent getInstance(); final void postTracking(JsonObject events); JsonObject provision(String key); String deProvision(boolean isTokenExpired); void instanceConfigUpdated(); void start(); void sendUSBInfoFromHalToController(); void sendHWInfoFromHalToController(); String getCheckUpgradeReadyReport(); void changeReadInterval();  }### Answer:
@Test public void testGetInstanceIsSameAsMock() { assertSame(fieldAgent, FieldAgent.getInstance()); }