import java.util.concurrent.TimeUnit;

/**
 * Factory methods for {@link ExecutorService} for testing.
 *
 * @author Chris Nokleberg
 * @since 14.0
 */
@GwtIncompatible
public final class TestingExecutors {
  private TestingExecutors() {}

  /**
   * Returns a {@link ScheduledExecutorService} that never executes anything.
   *
   * <p>The {@code shutdownNow} method of the returned executor always returns an empty list despite

          }
        };
    ScheduledFuture<?> future =
        TestingExecutors.noOpScheduledExecutor().schedule(task, 10, MILLISECONDS);
    Thread.sleep(20);
    assertFalse(taskDone);
    assertFalse(future.isDone());
  }

  public void testNoOpScheduledExecutorShutdown() {
    ListeningScheduledExecutorService executor = TestingExecutors.noOpScheduledExecutor();
    assertFalse(executor.isShutdown());

import static org.junit.Assert.assertThrows;

import com.google.common.testing.TearDown;
import com.google.common.testing.TearDownStack;
import com.google.common.util.concurrent.testing.TestingExecutors;
import java.lang.Thread.UncaughtExceptionHandler;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import static org.junit.Assert.assertThrows;

import com.google.common.testing.TearDown;
import com.google.common.testing.TearDownStack;
import com.google.common.util.concurrent.testing.TestingExecutors;
import java.lang.Thread.UncaughtExceptionHandler;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

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