code: def make_undirected(G):
      G.add_edges(G.edges()[1], G.edges()[0])
      return G
  
imports: import os
  import pickle
  import random
  import time
  import dgl
  import numpy
  import scipy.sparse
  import torch
  from dgl.data.utils import _get_dgl_url, download, extract_archive, get_download_dir
  from torch.utils.data import DataLoader
label_desc: Use image node_id 3 for calling a global function with example usage: make_undirected(G) and returns: G