def htlcs(self, subject: HTLCOwner, ctn: int = None) -> Sequence[Tuple[Direction, UpdateAddHtlc]]:
        """Return the list of HTLCs in subject's ctx at ctn."""
        assert type(subject) is HTLCOwner
        if ctn is None:
            ctn = self.ctn_oldest_unrevoked(subject)
        l = []
        l += [(SENT, x) for x in self.htlcs_by_direction(subject, SENT, ctn).values()]
        l += [(RECEIVED, x) for x in self.htlcs_by_direction(subject, RECEIVED, ctn).values()]
        return l
Return the list of HTLCs in subject's ctx at ctn.
electrum/lnhtlc.py