Get a getmore message.

def get_message(self, dummy0, dummy1, use_cmd=False):
        """Get a getmore message."""

        ns = _UJOIN % (self.db, self.coll)

        if use_cmd:
            ns = _UJOIN % (self.db, "$cmd")
            spec = self.as_command()[0]

            return query(0, ns, 0, -1, spec, None, self.codec_options)

        return get_more(ns, self.ntoreturn, self.cursor_id)