def get_node(self, node, parent=None):
        if self.data is None:
            return None

        if parent is None:
            nodes = self.data.xpath(node)
        else:
            nodes = parent.xpath(node)
        if len(nodes) != 1:
            return None

        return nodes[0]
No polling needed.
dataset/ETHPy150Open PublicMapping/DistrictBuilder/django/publicmapping/redistricting/__init__.py/StoredConfig.get_node--crossover with--dataset/ETHPy150Open home-assistant/home-assistant/homeassistant/components/light/mysensors.py/MySensorsLight.should_poll