@Override
          public Runnable apply(Runnable runnable) {
            return new ForwardingRunnable(runnable);
          }
        });
  }

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

          @Override
          public Runnable apply(Runnable runnable) {
            return new ForwardingRunnable(runnable);
          }
        });
  }

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