code: def test_expected_graph(self):
      graph = next(self._reader)
      with self.subTest("test_graph_equality"):
          tree.map_structure(
              np.testing.assert_almost_equal, graph, self._test_graph
          )
      with self.subTest("stop_iteration"):
          # One element in the dataset, so should have stop iteration.
          with self.assertRaises(StopIteration):
              next(self._reader)
  
file_path: jraph/jraph/ogb_examples/data_utils_test.py
imports: import pathlib
  from absl.testing import absltest
  from absl.testing import parameterized
  import jraph
  from jraph.ogb_examples import data_utils
  import numpy
  import tree
label_desc: Use image node_id 3 for calling the DataUtilsTest obj's underlying member method code with example usage: obj.test_expected_graph() without return types