def upload_part_from_file(self, fp, part_num, headers=None, replace=True,
                              cb=None, num_cb=10, policy=None, md5=None,
                              size=None):
        """
        Upload another part of this MultiPart Upload.
        
        :type fp: file
        :param fp: The file object you want to upload.
        
        :type part_num: int
        :param part_num: The number of this part.

        The other parameters are exactly as defined for the
        :class:`boto.s3.key.Key` set_contents_from_file method.
        """
        if part_num < 1:
            raise ValueError('Part numbers must be greater than zero')
        query_args = 'uploadId=%s&partNumber=%d' % (self.id, part_num)
        key = self.bucket.new_key(self.key_name)
        key.set_contents_from_file(fp, headers, replace, cb, num_cb, policy,
                                   md5, reduced_redundancy=False,
                                   query_args=query_args, size=size)