code: def test_getattr(self):
      f = FlatMap(dict(a=1, b=2))
      with self.assertRaisesRegex(AttributeError, "not supported"):
          _ = f.a
  
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 2 for calling the FlatMappingTest obj's underlying member method code with example usage: obj.test_getattr() without return types