code: def collate_fn(self, batch) -> Tuple[torch.Tensor, torch.Tensor]:
      batch = [data for data in batch if data is not None]
      imgs, bboxes = list(zip(*batch))
  
      imgs = torch.stack(imgs)
  
      for i, boxes in enumerate(bboxes):
          boxes[:, 0] = i
      bboxes = torch.cat(bboxes, 0)
  
      return imgs, bboxes
  
imports: import os
  import warnings
  from typing import Tuple, List
  import cv2
  import numpy
  import torch
  from torch.utils.data import Dataset
  from torchvision import transforms
  from ....yolov3.utils import prepare_image
label_desc: Use image node_id 9 for calling the LoadImagesAndLabels obj's underlying member method code with example usage: obj.collate_fn(batch) and returns: imgs,  bboxes