@Override
    public void failed(Exception ex) {
        httpAsyncRequestProducer.failed(ex);
    }
@Test
    public void failed() {
        final HttpAsyncRequestProducer delegate = Mockito.mock(HttpAsyncRequestProducer.class);
        final HttpAsyncRequestProducerDecorator decorator = new HttpAsyncRequestProducerDecorator(
                delegate, null, null);
        decorator.failed(null);
        Mockito.verify(delegate, Mockito.times(1)).failed(null);
    }