code: def test_nested_map(self):
      inp = {"a": ([0, 1], 2), "b": _TestNamedtuple(3)}
      out = {"a": ([1, 2], 3), "b": _TestNamedtuple(4)}
      self.assertEqual(fastmath.nested_map(lambda x: x + 1, inp), out)
  
imports: import collections
  from absl.testing import parameterized
  import gin
  import jax.numpy
  import numpy
  from tensorflow import test
  from trax import fastmath
label_desc: Use image node_id 7 for calling the BackendTest obj's underlying member method code with example usage: obj.test_nested_map() without return types