langchain/llms/anyscale.py/Anyscale/validate_environment
class Anyscale:    def validate_environment(cls, values: Dict) -> Dict:
        """Validate that api key and python package exists in environment."""
        anyscale_service_url = get_from_dict_or_env(
            values, "anyscale_service_url", "ANYSCALE_SERVICE_URL"
        )
        anyscale_service_route = get_from_dict_or_env(
            values, "anyscale_service_route", "ANYSCALE_SERVICE_ROUTE"
        )
        anyscale_service_token = get_from_dict_or_env(
            values, "anyscale_service_token", "ANYSCALE_SERVICE_TOKEN"
        )
        try:
            anyscale_service_endpoint = f"{anyscale_service_url}/-/route"
            headers = {"Authorization": f"Bearer {anyscale_service_token}"}
            requests.get(anyscale_service_endpoint, headers=headers)
        except requests.exceptions.RequestException as e:
            raise ValueError(e)
        values["anyscale_service_url"] = anyscale_service_url
        values["anyscale_service_route"] = anyscale_service_route
        values["anyscale_service_token"] = anyscale_service_token
        return values