### Question:
ResourceConsumptionManager implements IOFogModule { private long getAvailableDisk() { logDebug("Start get available disk"); File[] roots = File.listRoots(); long freeSpace = 0; for (File f : roots) { freeSpace += f.getUsableSpace(); } logDebug("Finished get available disk : " + freeSpace); return freeSpace; } private  ResourceConsumptionManager(); @Override int getModuleIndex(); @Override String getModuleName(); static ResourceConsumptionManager getInstance(); void instanceConfigUpdated(); void start();  }### Answer:
@Test public void testGetAvailableDisk() throws Exception{ method = ResourceConsumptionManager.class.getDeclaredMethod("getAvailableDisk"); method.setAccessible(true); long output = (long) method.invoke(resourceConsumptionManager); PowerMockito.verifyStatic(LoggingService.class, Mockito.atLeastOnce()); LoggingService.logDebug(MODULE_NAME, "Start get available disk"); PowerMockito.verifyStatic(LoggingService.class, Mockito.atLeastOnce()); LoggingService.logDebug(MODULE_NAME, "Finished get available disk : " + output); }