class_docstr: Load data from disk
      
code: def _extract_sentences(self, file):
      with open(file) as f:
          content = f.read().strip()
          sentences = content.split("\n\n")
          sentences = [self._extract_sentence(s) for s in sentences]
      return sentences
  
imports: import logging
  from os.path import join
  import pytorch_lightning
  from pytorch_lightning.loggers import WandbLogger
  from torch.optim import AdamW
  import torch.nn
  import torch
  from torchmetrics import F1
  from torch.utils.data import DataLoader, Dataset
  from transformers import AutoTokenizer, AutoModel
label_desc: Use image node_id 3 for calling the TokenClassificationCorpus obj's underlying member method code with example usage: obj._extract_sentences(file) and returns: sentences