code: def get_torrent_file(self, fp, headers=None, cb=None, num_cb=10):
          
          return self.get_file(fp, headers, cb, num_cb, torrent=True)
docs: Get a torrent file (see to get_file)
  
          :type fp: file
          :param fp: The file pointer of where to put the torrent
  
          :type headers: dict
          :param headers: Headers to be passed
  
          :type cb: function
          :param cb: a callback function that will be called to report
                     progress on the upload.  The callback should accept
                     two integer parameters, the first representing the
                     number of bytes that have been successfully
                     transmitted to S3 and the second representing the
                     size of the to be transmitted object.
  
          :type cb: int
          :param num_cb: (optional) If a callback is specified with
                         the cb parameter this parameter determines the
                         granularity of the callback by defining
                         the maximum number of times the callback will
                         be called during the file transfer.