code: def test_traverse_nested(self):
      nested_structure = {
          "layer": {"a": [1, 2, 3], "b": {object()}, "c": {"a": "b"}}
      }
      expected = [
          ("layer", x, nested_structure["layer"][x])
          for x in ("a", "b", "c")
      ]
      actual = list(filtering.traverse(nested_structure))
      self.assertEqual(expected, actual)
  
imports: import collections
  from collections.abc import Sequence
  import itertools
  import re
  import types
  from typing import Any, Callable
  from absl.testing import absltest
  from absl.testing import parameterized
  from haiku._src import basic
  from haiku._src import data_structures
  from haiku._src import filtering
  from haiku._src import transform
  import jax
  import jax.numpy
label_desc: Use image node_id 6 for calling the FilteringTest obj's underlying member method code with example usage: obj.test_traverse_nested() without return types