@Test
public void callableJustGetsInvokedWithNoWrappers() throws Exception {

    impl = new ServiceWrapperChain(new ArrayList<ServiceWrapper>());
    final Object out = new Object();
    Callable<Object> c = new Callable<Object>() {
        public Object call() throws Exception {
            return out;
        }
    };
    assertSame(out, impl.invoke(c));
}