code: def testCallFnLeafArgs(self, arg):
      def fn(arg):
          return arg
  
      self.assertEqual(arg, fn(arg))
  
imports: import collections
  from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import deterministic
  from tensorflow_probability.python.distributions import half_cauchy
  from tensorflow_probability.python.distributions import joint_distribution_auto_batched
  from tensorflow_probability.python.distributions import normal
  from tensorflow_probability.python.internal import nest_util
  from tensorflow_probability.python.internal import test_util
  from tensorflow.python.util import nest
label_desc: Use image node_id 7 for calling the NestUtilTest obj's underlying member method code with example usage: obj.testCallFnLeafArgs(arg) and returns: arg