@Override
          public Integer call() {
            taskDone = true;
            return 6;
          }
        };
    Future<Integer> future =
        TestingExecutors.sameThreadScheduledExecutor().schedule(task, 10000, MILLISECONDS);
    assertTrue("Should run callable immediately", taskDone);
    assertEquals(6, (int) future.get());
  }

   * already have been executed.
   *
   * @since 32.0.0 (taking the place of a method with a different return type from 15.0)
   */
  public static ListeningScheduledExecutorService sameThreadScheduledExecutor() {
    return new SameThreadScheduledExecutorService();
  }

  private static final class NoOpScheduledExecutorService extends AbstractListeningExecutorService
      implements ListeningScheduledExecutorService {

 * from an existing {@link ExecutorService}, call {@link
 * MoreExecutors#listeningDecorator(ExecutorService)}.
 *
 * @author Chris Povirk
 * @since 10.0
 */
@DoNotMock(
    "Use TestingExecutors.sameThreadScheduledExecutor, or wrap a real Executor from "
        + "java.util.concurrent.Executors with MoreExecutors.listeningDecorator")
@GwtIncompatible
@ElementTypesAreNonnullByDefault

import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible
class SameThreadScheduledExecutorService extends AbstractExecutorService

import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible
class SameThreadScheduledExecutorService extends AbstractExecutorService