langchain/tools/openapi/utils/openapi_utils.py/OpenAPISpec/_alert_unsupported_spec
class OpenAPISpec:    def _alert_unsupported_spec(obj: dict) -> None:
        """Alert if the spec is not supported."""
        warning_message = (
            " This may result in degraded performance."
            + " Convert your OpenAPI spec to 3.1.* spec"
            + " for better support."
        )
        swagger_version = obj.get("swagger")
        openapi_version = obj.get("openapi")
        if isinstance(openapi_version, str):
            if openapi_version != "3.1.0":
                logger.warning(
                    f"Attempting to load an OpenAPI {openapi_version}"
                    f" spec. {warning_message}"
                )
            else:
                pass
        elif isinstance(swagger_version, str):
            logger.warning(
                f"Attempting to load a Swagger {swagger_version}"
                f" spec. {warning_message}"
            )
        else:
            raise ValueError(
                "Attempting to load an unsupported spec:"
                f"\n\n{obj}\n{warning_message}"
            )