code: def _download(self):
          
          print("Downloading!")
          def parse(result):
              print("Got %r back from Yahoo." % (result,))
              values = result.strip().split(",")
              self._value = float(values[1])
          d = getPage(
              "http://download.finance.yahoo.com/d/quotes.csv?e=.csv&f=c4l1&s=%s=X"
              % (self._name,))
          d.addCallback(parse)
          d.addErrback(log.err)
          return d
docs: Download the page.