def get_torrent_file(self, fp, headers=None, cb=None, num_cb=10):
        """
        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.

        """
        return self.get_file(fp, headers, cb, num_cb, torrent=True)