@Test
public void runnableWithTwoNullWrappersThreadsProperly() throws Exception {

    final Flag f = new Flag();
    Runnable r = new Runnable() {
        public void run() {
            f.set = true;
        }
    };
    NullWrapper wrapper1 = new NullWrapper();
    NullWrapper wrapper2 = new NullWrapper();
    impl = new ServiceWrapperChain(Arrays.asList((ServiceWrapper)wrapper1, (ServiceWrapper)wrapper2));
    impl.invoke(r);
    assertTrue(wrapper1.invokedRunnable);
    assertTrue(wrapper2.invokedRunnable);
    assertTrue(f.set);
}