@Override
  public <T> T invokeAny(Collection<? extends Callable<T>> tasks) throws InterruptedException, ExecutionException {
    return delegate.invokeAny(tasks);
  }
@Test
  public void invokeAny_delegates_to_executorService() throws ExecutionException, InterruptedException {
    underTest.invokeAny(CALLABLES);

    inOrder.verify(executorService).invokeAny(CALLABLES);
    inOrder.verifyNoMoreInteractions();
  }