code: def __getitem__(self, idx):
      document_path = self.documents[idx]
      document_name = document_path.split("/")[-1]
  
      items = []
  
      with open(document_path, encoding="utf-8") as source:
          raw_text = source.readlines()
          for obj in raw_text:
              text = json.loads(obj)["text"]
              text = re.sub("\\n", " ", text)
              text = re.sub("\\s+", " ", text)
              items.append(text)
  
      return items
  
imports: import re
  import torch
  import torch.nn
  import torch.nn.functional
  from torch.utils.data import Dataset, DataLoader, random_split
  from tqdm import tqdm
  from reformer_pytorch import Reformer, ReformerLM
  from transformers import BertTokenizer, PreTrainedTokenizer
  from fairseq.optim.adafactor import Adafactor
  import os
  import json
  import logging
  from datetime import datetime
label_desc: Use image node_id 3 for calling the WikiDataset obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: items