code: def __len__(self):
      return len(self.data_list)
  
file_path: pfe-net/util/dataset.py
imports: import os
  import os.path
  import cv2
  import numpy
  from torch.utils.data import Dataset
  import torch.nn.functional
  import torch
  import random
  import time
  from tqdm import tqdm
label_desc: Use image node_id 2 for calling the SemData obj's underlying member method code with example usage: obj.__len__() and returns: len