runnables.poll().execute();
      }
    }

    private static class RunnableExecutorPair {
      final Runnable runnable;
      final Executor executor;

      RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);

/**
 * Static utility methods pertaining to the {@link Runnable} interface.
 *
 * @since 16.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Runnables {

  private static final Runnable EMPTY_RUNNABLE =
      new Runnable() {
        @Override
        public void run() {}
      };

  /** Returns a {@link Runnable} instance that does nothing when run. */

  }

  public void testExceptionsCaught() {
    list.add(THROWING_RUNNABLE, directExecutor());
    list.execute();
    list.add(THROWING_RUNNABLE, directExecutor());
  }

  public void testNulls() {
    new NullPointerTester().testAllPublicInstanceMethods(new ExecutionList());
  }

  private static final Runnable THROWING_RUNNABLE =
      new Runnable() {
        @Override
        public void run() {

    @Override
    public void execute(Runnable runnable) {
      assertThat(runnable).isInstanceOf(TrustedListenableFutureTask.class);
      runnable.run();
    }

    @Override
    public void shutdown() {}

    @Override
    public List<Runnable> shutdownNow() {
      return ImmutableList.of();
    }

    @Override
    public boolean isShutdown() {
      return false;
    }

    @Override

        runnables.poll().execute();
      }
    }

    private static class RunnableExecutorPair {
      final Runnable runnable;
      final Executor executor;

      RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);

    ThrowingRunnable runnable = new ThrowingRunnable(5, ex);
    future = service.scheduleAtFixedRate(runnable, 1, 1, TimeUnit.MILLISECONDS);
    assertExecutionException(future, ex);
    assertEquals(5, runnable.count);
    assertEquals(0, delegate.getQueue().size());

    runnable = new ThrowingRunnable(5, ex);
    future = service.scheduleWithFixedDelay(runnable, 1, 1, TimeUnit.MILLISECONDS);

                  + runnable
                  + " with executor "
                  + executor,
              e);
    }
  }

  private static final class RunnableExecutorPair {
    final Runnable runnable;
    final Executor executor;
    @CheckForNull RunnableExecutorPair next;

    RunnableExecutorPair(

    }

    @Override
    public T call() throws Exception {
      return delegate.call();
    }
  }

  private static final class WrappedRunnable implements Runnable {
    private final Runnable delegate;

    public WrappedRunnable(Runnable delegate) {
      this.delegate = delegate;
    }

    @Override
    public void run() {
      delegate.run();
    }
  }

    }

    @Override
    public T call() throws Exception {
      return delegate.call();
    }
  }

  private static final class WrappedRunnable implements Runnable {
    private final Runnable delegate;

    public WrappedRunnable(Runnable delegate) {
      this.delegate = delegate;
    }

    @Override
    public void run() {
      delegate.run();
    }
  }

    tester.testForwarding(
        Runnable.class,
        new Function<Runnable, Runnable>() {
          @Override
          public Runnable apply(final Runnable runnable) {
            return new ForwardingRunnable(runnable);
          }
        });
  }

  public void testToStringForwarding() {
    tester.testForwarding(
        Runnable.class,
        new Function<Runnable, Runnable>() {
          @Override