### Question:
ScreenTracker extends SimpleActivityLifecycleCallbacks implements PhialScopeNotifier.OnScopeChangedListener { void destroy() { listeners.clear(); currentScreen.clearActivity(); }  void addListener(ScreenListener listener); void removeListener(ScreenListener listener); Screen getCurrentScreen(); @Override void onActivityResumed(Activity activity); @Override void onActivityPaused(Activity activity); @Override void onEnterScope(String scopeName, View view); @Override void onExitScope(String scopeName); boolean matchesAny(Set<TargetScreen> targetScreen); View findTarget(int id);  }### Answer:
@Test public void destroy() throws Exception { screenTracker.destroy(); assertNull(screenTracker.getCurrentScreen().getActivity()); }