code: def _flatten_past_key_values_(self, flattened_output, name, idx, t):
      flattened_output[f"{name}.{idx}.key"] = t[0]
      flattened_output[f"{name}.{idx}.value"] = t[1]
  
imports: import copy
  import dataclasses
  import warnings
  from abc import ABC, abstractmethod
  from collections import OrderedDict
  from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, List, Mapping, Optional, Tuple, Union
  import numpy
  from packaging import version
  from ..utils import TensorType, is_torch_available, is_vision_available, logging
  from .utils import ParameterFormat, compute_effective_axis_dimension, compute_serialized_parameters_size
label_desc: Use image node_id 9 for calling the OnnxConfigWithPast obj's underlying member method code with example usage: obj._flatten_past_key_values_(flattened_output, name, idx, t) without return types