import com.google.common.util.concurrent.testing.MockFutureListener;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;

/**
 * Unit tests for any listenable future that chains other listenable futures. Unit tests need only
 * override buildChainingFuture and getSuccessfulResult, but they can add custom tests as needed.
 *
 * @author Nishant Thakkar
 */

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Used to test listenable future implementations.
 *
 * @author Sven Mawson
 */
public class ListenableFutureTester {

  private final ExecutorService exec;
  private final ListenableFuture<?> future;

  }

  @Override
  protected void tearDown() throws Exception {

    // Make sure we have no waiting threads.
    latch.countDown();
  }

  /** Constructs a listenable future with a value available after the latch has counted down. */
  protected abstract <V> ListenableFuture<V> createListenableFuture(
      V value, @Nullable Exception except, CountDownLatch waitOn);

  }

  @Override
  protected void tearDown() throws Exception {

    // Make sure we have no waiting threads.
    latch.countDown();
  }

  /** Constructs a listenable future with a value available after the latch has counted down. */
  protected abstract <V> ListenableFuture<V> createListenableFuture(
      V value, @Nullable Exception except, CountDownLatch waitOn);