public WebCrawler(ICrawlingStats crawlingStats, IResultWriter resultWriter, IClock clock)
{
_crawlingStats = crawlingStats;
_resultWriter = resultWriter;
_clock = clock;
_webCrawler = new PoliteWebCrawler();
_webCrawler.PageCrawlCompletedAsync += ProcessPageCrawlCompleted;
_startCrawlingTime = _clock.FormattedCurrentTime();
//_resultFilePath = System.Configuration.ConfigurationManager.AppSettings["ResultFileName"];
}