def _Initialize(self, http, url):
        """Initialize this download by setting self.http and self.url.

        We want the user to be able to override self.http by having set
        the value in the constructor; in that case, we ignore the provided
        http.

        Args:
          http: An httplib2.Http instance or None.
          url: The url for this transfer.

        Returns:
          None. Initializes self.
        """
        self.EnsureUninitialized()
        if self.http is None:
            self.__http = http or http_wrapper.GetHttp()
        self.__url = url
Initialize this download by setting self.http and self.url.

        We want the user to be able to override self.http by having set
        the value in the constructor; in that case, we ignore the provided
        http.

        Args:
          http: An httplib2.Http instance or None.
          url: The url for this transfer.

        Returns:
          None. Initializes self.