code: def collate_fn(batch):
      images, targets = list(zip(*batch))
      batched_imgs = cat_list(images, fill_value=0)
      batched_targets = cat_list(targets, fill_value=255)
      return batched_imgs, batched_targets
  
file_path: deep-learning-for-image-processing/pytorch_segmentation/unet/my_dataset.py
imports: import os
  from PIL import Image
  import numpy
  from torch.utils.data import Dataset
label_desc: Use image node_id 4 for calling the DriveDataset obj's underlying member method code with example usage: obj.collate_fn(batch) and returns: batched_imgs,  batched_targets