verify(urlQueueService, times(0)).offerAll(anyString(), any());
    }

    /**
     * Test storeChildUrls with valid URLs.
     */
    @SuppressWarnings("unchecked")
    public void test_storeChildUrls_validUrls() throws Exception {
        final Set<RequestData> childUrlList = new HashSet<>();
        childUrlList.add(RequestDataBuilder.newRequestData().url("http://example.com/child1").build());