code: def test_resnet18_quantitrain_image_folder_pngze(self):
      resnet18 = vision.resnet18(
          pretrained=False, include_top=False, freeze=True
      )
      train_torch_lightning(resnet18, root_dir1, batch_size)
      train_torch_lightning(resnet18, root_dir2, batch_size)
  
file_path: BigDL/python/nano/test/pytorch/tests/vision/test_imagefolder.py
imports: import pytest
  import os
  from unittest import TestCase
  from bigdl.nano.pytorch.vision.models import vision
  from test.pytorch.utils._train_imagefolder import train_torch_lightning
label_desc: Use image node_id 1 for calling the TestImageFolder obj's underlying member method code with example usage: obj.test_resnet18_quantitrain_image_folder_pngze() without return types