langchain/retrievers/self_query/base.py/SelfQueryRetriever/validate_translator
class SelfQueryRetriever:    def validate_translator(cls, values: Dict) -> Dict:
        """Validate translator."""
        if "structured_query_translator" not in values:
            vectorstore_cls = values["vectorstore"].__class__
            values["structured_query_translator"] = _get_builtin_translator(
                vectorstore_cls
            )
        return values