import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.AbstractFuture;
import com.google.common.util.concurrent.AbstractListeningExecutorService;
import com.google.common.util.concurrent.ListenableScheduledFuture;
import com.google.common.util.concurrent.ListeningScheduledExecutorService;
import com.google.common.util.concurrent.MoreExecutors;

import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.TimeUnit;

/** See newDirectExecutorService javadoc for behavioral notes. */
@GwtIncompatible
final class DirectExecutorService extends AbstractListeningExecutorService {

  /** Lock used whenever accessing the state variables (runningTasks, shutdown) of the executor */
  private final Object lock = new Object();

  /*

        ? (ListeningScheduledExecutorService) delegate
        : new ScheduledListeningDecorator(delegate);
  }

  @GwtIncompatible // TODO
  private static class ListeningDecorator extends AbstractListeningExecutorService {
    private final ExecutorService delegate;

    ListeningDecorator(ExecutorService delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override