Push extends AbstractAppCenterService { public static synchronized Push getInstance() { if (sInstance == null) { sInstance = new Push(); } return sInstance; } private  Push(); static synchronized Push getInstance(); static AppCenterFuture<Boolean> isEnabled(); static AppCenterFuture<Void> setEnabled(boolean enabled); static void setListener(PushListener pushListener); @SuppressWarnings("JavadocReference") static void checkLaunchedFromNotification(Activity activity, Intent intent); @Deprecated static void setSenderId(@SuppressWarnings("SameParameterValue") String senderId); static void enableFirebaseAnalytics(@NonNull Context context); @Override String getServiceName(); @Override Map<String, LogFactory> getLogFactories(); @Override synchronized void onStarted(@NonNull Context context, @NonNull Channel channel, String appSecret, String transmissionTargetToken, boolean startedFromApp); @Override void onActivityCreated(Activity activity, Bundle savedInstanceState); @Override void onActivityStarted(Activity activity); @Override synchronized void onActivityResumed(Activity activity); @Override void onActivityPaused(Activity activity);  }
@Test public void singleton() { assertSame(Push.getInstance(), Push.getInstance()); }