code: def collate(samples):
      graphs, cat = map(list, zip(*samples))
      return dgl.batch(graphs), cat
  
file_path: dgl/examples/pytorch/pointcloud/point_transformer/train_partseg.py
imports: import argparse
  import time
  from functools import partial
  import dgl
  import numpy
  import torch
  import torch.optim
  import tqdm
  from point_transformer import PartSegLoss, PointTransformerSeg
  from ShapeNet import ShapeNet
  from torch.utils.data import DataLoader
label_desc: Use image node_id 1 for calling a global function with example usage: collate(samples) and returns: dgl,  cat