new_contents: from scrapy.spider import BaseSpider
  
  class CnnSpider(BaseSpider):
      name = 'cnn'
      allowed_domains = ['www.cnn.com']
      start_urls = [
          'http://www.cnn.com/',
      ]
  
      def parse(self, response):
          open('homepage.html', 'wb').write(response.body)
  
subject: add trivial CNN homepage downloader spider