protected void extractAndAddRequests(Page page, boolean spawnUrl) {
        if (spawnUrl && CollectionUtils.isNotEmpty(page.getTargetRequests())) {
            for (Request request : page.getTargetRequests()) {
                addRequest(request);
            }
        }
    }
Process specific urls without url discovering.

@param urls urls to process
webmagic-core/src/main/java/us/codecraft/webmagic/Spider.java