langchain/tools/openapi/utils/openapi_utils.py/OpenAPISpec/get_operation
class OpenAPISpec:    def get_operation(self, path: str, method: str) -> Operation:
        """Get the operation object for a given path and HTTP method."""
        path_item = self._get_path_strict(path)
        operation_obj = getattr(path_item, method, None)
        if not isinstance(operation_obj, Operation):
            raise ValueError(f"No {method} method found for {path}")
        return operation_obj