def ch_stop_time(self, *channels: List[Channel]) -> int:
        """Return maximum time of timeslots over all channels.

        Args:
            *channels: Channels over which to obtain stop time.
        """
        intervals = list(itertools.chain(*(self._table[chan] for chan in channels
                                           if chan in self._table)))
        if intervals:
            return max((interval.end for interval in intervals))
        return 0
Return maximum time of timeslots over all channels.

        Args:
            *channels: Channels over which to obtain stop time.