def _call_when_changed(self, ticks=None, state=None):
        """
        Overridden to provide default ticks from the local Pi factory.

        .. warning::

            The local pin factory uses a seconds-based monotonic value for
            its ticks but you *must not* rely upon this behaviour. Ticks are
            an opaque value that should only be compared with the associated
            :meth:`Factory.ticks_diff` method.
        """
        super(LocalPiPin, self)._call_when_changed(
            self._factory.ticks() if ticks is None else ticks,
            self.state if state is None else state)