langchain/llms/writer.py/Writer/validate_environment
class Writer:    def validate_environment(cls, values: Dict) -> Dict:
        """Validate that api key and organization id exist in environment."""

        writer_api_key = get_from_dict_or_env(
            values, "writer_api_key", "WRITER_API_KEY"
        )
        values["writer_api_key"] = writer_api_key

        writer_org_id = get_from_dict_or_env(values, "writer_org_id", "WRITER_ORG_ID")
        values["writer_org_id"] = writer_org_id

        return values