code: def download(self, url):
          
          store = DocumentStore()
          fp = store.open(url)
          if fp is None:
              fp = self.options.transport.open(Request(url))
          content = fp.read()
          fp.close()
          ctx = self.plugins.document.loaded(url=url, document=content)
          content = ctx.document
          sax = Parser()
          return sax.parse(string=content)
docs: Download the docuemnt.
          @param url: A document url.
          @type url: str.
          @return: A file pointer to the docuemnt.
          @rtype: file-like