code: def test_copy(self, clone):
      before = data_structures.to_immutable_dict(dict(a=dict(b=1, c=2)))
      after = clone(before)
      self.assertIsNot(before, after)
      self.assertEqual(before, after)
      self.assertEqual(after, {"a": {"b": 1, "c": 2}})
      before_dict = data_structures.to_haiku_dict(before)
      jax.tree_util.tree_map(self.assertEqual, before_dict, after)
  
imports: import collections
  import copy
  import pickle
  import threading
  from absl.testing import absltest
  from absl.testing import parameterized
  import cloudpickle
  import dill
  from haiku._src import data_structures
  import jax
  import tree
label_desc: Use image node_id 11 for calling the FlatMappingTest obj's underlying member method code with example usage: obj.test_copy(clone) without return types