import java.util.List;
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();

  /*