langchain/tools/openapi/utils/openapi_utils.py/OpenAPISpec/_get_root_referenced_request_body
class OpenAPISpec:    def _get_root_referenced_request_body(
        self, ref: Reference
    ) -> Optional[RequestBody]:
        """Get the root request Body or err."""
        request_body = self._get_referenced_request_body(ref)
        while isinstance(request_body, Reference):
            request_body = self._get_referenced_request_body(request_body)
        return request_body