code: def base_url(self):
          
          return '{proto}://{host}:{port}{url_path}'.format(
              proto=self.protocol,
              host=self.host,
              port=self.port,
              url_path=self.url_path,
          )
docs: A base_url that will be used to construct the final
          URL we're going to query against.
  
          :returns: A URL of the form: ``proto://host:port``.
          :rtype: :obj:`string`