code: def testNestMapStructure(self):
      k = object_identity._ObjectIdentityWrapper("k")
      v1 = object_identity._ObjectIdentityWrapper("v1")
      v2 = object_identity._ObjectIdentityWrapper("v2")
      struct = tf.nest.map_structure(
          lambda a, b: (a, b), {k: v1}, {k: v2}
      )
      self.assertEqual(struct, {k: (v1, v2)})
  
file_path: agents/tf_agents/utils/object_identity_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import tensorflow
  from tf_agents.utils import object_identity
label_desc: Use image node_id 3 for calling the ObjectIdentityWrapperTest obj's underlying member method code with example usage: obj.testNestMapStructure() without return types