code: def test_pickling_graph(g, idtype):
      g = g.astype(idtype)
      new_g = _reconstruct_pickle(g)
      check_graph_equal(g, new_g, check_feature=True)
  
imports: import io
  import pickle
  import unittest
  import backend
  import dgl
  import dgl.function
  import networkx
  import pytest
  import scipy.sparse
  from dgl.graph_index import create_graph_index
  from dgl.utils import toindex
  from utils import assert_is_identical, assert_is_identical_hetero, check_graph_equal, get_cases, parametrize_idtype
label_desc: Use image node_id 9 for calling a global function with example usage: test_pickling_graph(g, idtype) without return types