code: def test_init_from_dict(self):
      o = dict(a=1, b=2)
      f = FlatMap(o)
      self.assertEqual(o, f)
      o["a"] = 2
      self.assertEqual(f["a"], 1)
      self.assertNotEqual(o, f)
  
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 1 for calling the FlatMappingTest obj's underlying member method code with example usage: obj.test_init_from_dict() without return types