langchain/document_loaders/weather.py/WeatherDataLoader/lazy_load
class WeatherDataLoader:    def lazy_load(
        self,
    ) -> Iterator[Document]:
        """Lazily load weather data for the given locations."""
        for place in self.places:
            metadata = {"queried_at": datetime.now()}
            content = self.client.run(place)
            yield Document(page_content=content, metadata=metadata)