code: def get_config(self) -> List[_MixedDatasetConfig]:
      if self._config is None:
          if not self.changed():
              raise RuntimeError("Failed to load config")
          if self._config is None:
              raise RuntimeError("Failed to load config")
      return self._config
  
imports: from collections import OrderedDict
  import multiprocessing
  import os
  from queue import Empty
  from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
  from typing_extensions import TypedDict
  from ...dataset import DistributedDataset
  from ...tokenizers import CPMBeeTokenizer
  from ...utils.config import load_dataset_config
  import numpy
  import time
  from numpy.typing import NDArray
  import torch
  import bmtrain
  import importlib.machinery
  import importlib.util
  import types
  import random
label_desc: Use image node_id 3 for calling the _MixedDatasetConfigMananger obj's underlying member method code with example usage: obj.get_config() and returns: self