TaskExecutor: Switch from LifecycleObserver to LifecycleEventObserver

import androidx.annotation.Nullable;

import androidx.annotation.WorkerThread;

import androidx.lifecycle.Lifecycle;

import androidx.lifecycle.LifecycleObserver;

import androidx.lifecycle.LifecycleEventObserver;

import androidx.lifecycle.LifecycleOwner;

import androidx.lifecycle.OnLifecycleEvent;

import java.util.ArrayList;

import java.util.List;

import java.util.concurrent.TimeoutException;

import java.util.function.Consumer;

public final class TaskExecutor implements LifecycleObserver {

public final class TaskExecutor implements LifecycleEventObserver {

    private static final String TAG = "TaskExecutor";

    private final ExecutorService executor = Executors.newFixedThreadPool(2);

    private final Handler handler = new Handler(Looper.getMainLooper());

    private final List<Future<?>> execFutures = new ArrayList<>(4);

    @Override

    public void onStateChanged(@NonNull LifecycleOwner source, @NonNull Lifecycle.Event event) {

        if (event == Lifecycle.Event.ON_DESTROY) {

            terminate(source);

        }

    }

    public synchronized <T> void runTask(@NonNull @WorkerThread Callable<T> callable,

                                         @NonNull @MainThread Consumer<T> consumer) {

        final Future<T> future = executor.submit(callable);

        }

    }

    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)

    public void terminate(@Nullable LifecycleOwner owner) {

        // Unsubscribe

        if (owner != null) {