private void onDownloaderFail(Request request) {
        if (site.getCycleRetryTimes() == 0) {
            sleep(site.getSleepTime());
        } else {
            // for cycle retry
            doCycleRetry(request);
        }
    }
Process specific urls without url discovering.

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