code: def __len__(self) -> int:
      return self.total_sentence_count
  
imports: import json
  from pathlib import Path
  from typing import Dict, Optional, Union
  import gdown.download_folder
  import PIL
  from torch.utils.data import Dataset
  import flair
  from flair.data import BoundingBox, Corpus, FlairDataset, Sentence, get_spans_from_bio
  from flair.datasets.base import find_train_dev_test_files
label_desc: Use image node_id 5 for calling the OcrJsonDataset obj's underlying member method code with example usage: obj.__len__() and returns: self