### Question:
ParsePush { public static Task<Void> unsubscribeInBackground(String channel) { return getPushChannelsController().unsubscribeInBackground(channel); } ParsePush();  ParsePush(ParsePush push); private  ParsePush(State.Builder builder); static Task<Void> subscribeInBackground(String channel); static void subscribeInBackground(String channel, SaveCallback callback); static Task<Void> unsubscribeInBackground(String channel); static void unsubscribeInBackground(String channel, SaveCallback callback); static Task<Void> sendMessageInBackground(String message,
      ParseQuery<ParseInstallation> query); static void sendMessageInBackground(String message, ParseQuery<ParseInstallation> query,
      SendCallback callback); static Task<Void> sendDataInBackground(JSONObject data,
      ParseQuery<ParseInstallation> query); static void sendDataInBackground(JSONObject data, ParseQuery<ParseInstallation> query,
      SendCallback callback); void setChannel(String channel); void setChannels(Collection<String> channels); void setQuery(ParseQuery<ParseInstallation> query); void setExpirationTime(long time); void setExpirationTimeInterval(long timeInterval); void clearExpiration(); void setPushTime(long time); @Deprecated void setPushToIOS(boolean pushToIOS); @Deprecated void setPushToAndroid(boolean pushToAndroid); void setData(JSONObject data); void setMessage(String message); Task<Void> sendInBackground(); void send(); void sendInBackground(SendCallback callback);  }### Answer:
@Test public void testUnsubscribeInBackgroundSuccess() throws Exception { ParsePushChannelsController controller = mock(ParsePushChannelsController.class); when(controller.unsubscribeInBackground(anyString())).thenReturn(Task.<Void>forResult(null)); ParseCorePlugins.getInstance().registerPushChannelsController(controller); ParseTaskUtils.wait(ParsePush.unsubscribeInBackground("test")); verify(controller, times(1)).unsubscribeInBackground("test"); }
@Test public void testUnsubscribeInBackgroundWithCallbackSuccess() throws Exception { final ParsePushChannelsController controller = mock(ParsePushChannelsController.class); when(controller.unsubscribeInBackground(anyString())).thenReturn(Task.<Void>forResult(null)); ParseCorePlugins.getInstance().registerPushChannelsController(controller); final Semaphore done = new Semaphore(0); final Capture<Exception> exceptionCapture = new Capture<>(); ParsePush.unsubscribeInBackground("test", new SaveCallback() { @Override public void done(ParseException e) { exceptionCapture.set(e); done.release(); } }); assertNull(exceptionCapture.get()); assertTrue(done.tryAcquire(1, 10, TimeUnit.SECONDS)); verify(controller, times(1)).unsubscribeInBackground("test"); }
@Test public void testUnsubscribeInBackgroundFail() throws Exception { ParsePushChannelsController controller = mock(ParsePushChannelsController.class); ParseException exception = new ParseException(ParseException.OTHER_CAUSE, "error"); when(controller.unsubscribeInBackground(anyString())) .thenReturn(Task.<Void>forError(exception)); ParseCorePlugins.getInstance().registerPushChannelsController(controller); Task<Void> pushTask = ParsePush.unsubscribeInBackground("test"); pushTask.waitForCompletion(); verify(controller, times(1)).unsubscribeInBackground("test"); assertTrue(pushTask.isFaulted()); assertSame(exception, pushTask.getError()); }
@Test public void testUnsubscribeInBackgroundWithCallbackFail() throws Exception { ParsePushChannelsController controller = mock(ParsePushChannelsController.class); final ParseException exception = new ParseException(ParseException.OTHER_CAUSE, "error"); when(controller.unsubscribeInBackground(anyString())) .thenReturn(Task.<Void>forError(exception)); ParseCorePlugins.getInstance().registerPushChannelsController(controller); ParsePush push = new ParsePush(); final Semaphore done = new Semaphore(0); final Capture<Exception> exceptionCapture = new Capture<>(); ParsePush.unsubscribeInBackground("test", new SaveCallback() { @Override public void done(ParseException e) { exceptionCapture.set(e); done.release(); } }); assertSame(exception, exceptionCapture.get()); assertTrue(done.tryAcquire(1, 10, TimeUnit.SECONDS)); verify(controller, times(1)).unsubscribeInBackground("test"); }