code: def __len__(self):
      return len(self.imgs)
  
file_path: gen-efficientnet-pytorch/data/dataset.py
imports: import torch.utils.data
  import os
  import re
  import torch
  from PIL import Image
label_desc: Use image node_id 3 for calling the Dataset obj's underlying member method code with example usage: obj.__len__() and returns: len