# if one handler func calls another, does that break anything?

        # maybe not?

        # no plan for sparql queries yet. Hook into a lower layer that

        # reveals all their statement fetches? Just make them always

        # new? Cache their results, so if i make the query again and

        # it gives the same result, I don't call the handler?

        self.currentFuncs.append(func)

        log.debug('graph.currentFuncs push %s', func)

        try:

        finally:

            self.currentFuncs.pop()

            log.debug('graph.currentFuncs pop %s. stack now has %s', func, len(self.currentFuncs))

    def runDepsOnNewPatch(self, p):

        """

        patch p just happened to the graph; call everyone back who

        might care, and then notice what data they depend on now

        """

        for func in self._watchers.whoCares(p):

            # todo: forget the old handlers for this func

            log.debug('runDepsOnNewPatch calling watcher %s', p)