def get_match_children(self):
        if self.match_children is not None:
            self.match_children = []
            for route in self.get_children():
                for r in route.get_match_routes():
                    self.match_children.append(r)

        for rv in self.match_children:
            yield rv
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/webapp2-2.3/webapp2_extras/routes.py/MultiRoute.get_match_children/operator `is` -> `is not`