code: def __getitem__(self, id_):
      if self.cached_data is None:
          return self.load_from_file(id_)
      else:
          return self.cached_data[id_]
  
imports: import json
  from collections import OrderedDict
  from pathlib import Path
  from typing import List
  import re
  import numpy
  import torch
  import torch.utils.data
  from tqdm import tqdm
  from gluoncv.torch.utils import coot_utils
label_desc: Use image node_id 2 for calling the ActivityNetVideoFeatureLoader obj's underlying member method code with example usage: obj.__getitem__(id_) and returns: self, self