class_docstr: 默认使用 List 存储数据
class_docstr_tok: ["\u9ed8\u8ba4\u4f7f\u7528","List","\u5b58\u50a8\u6570\u636e"]
code: def __getitem__(self, item):
      sample = self.file[item]
      return sample
  
file_path: DeepKE/src/deepke/attribution_extraction/standard/tools/dataset.py
imports: import torch
  from torch.utils.data import Dataset
  import os
  import sys
  from utils import load_pkl
label_desc: Use image node_id 2 for calling the CustomDataset obj's underlying member method code with example usage: obj.__getitem__(item) and returns: sample