### Question:
AppConfig extends GlideApplication { public ScreenUtils getScreenUtils() { return screenUtils; }  UtilitiesProvider getUtilsProvider(); @Override void onCreate(); @Override void onTerminate(); void runInBackground(Runnable runnable); static void toast(Context context, @StringRes int message); static void toast(Context context, String message); void runInApplicationThread(Runnable r); static synchronized AppConfig getInstance(); ImageLoader getImageLoader(); UtilsHandler getUtilsHandler(); void setMainActivityContext(@NonNull Activity activity); ScreenUtils getScreenUtils(); @Nullable Context getMainActivityContext(); ExplorerDatabase getExplorerDatabase(); UtilitiesDatabase getUtilitiesDatabase(); static final String TAG; }### Answer:
@Test public void testGetScreenUtils() { assertNull(AppConfig.getInstance().getScreenUtils()); MainActivity mock = mock(MainActivity.class); AppConfig.getInstance().setMainActivityContext(mock); assertNotNull(AppConfig.getInstance().getScreenUtils()); }