docstr: Tests that RNG variable is added to ConcreteFunction.variables.
code: def testFnVars(self):
      """Tests that RNG variable is added to ConcreteFunction.variables."""
      rng = random.Generator.from_seed(0)
  
      @def_function.function
      def f():
          return rng.normal([])
  
      concrete = f.get_concrete_function()
      self.assertIn(rng.state, concrete.variables)
  
imports: import os
  import re
  from absl.testing import parameterized
  import numpy
  from tensorflow.python.checkpoint import checkpoint
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import config
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.kernel_tests.random import util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_random_ops
  from tensorflow.python.ops import gen_stateful_random_ops
  from tensorflow.python.ops import logging_ops
  from tensorflow.python.ops import random_ops_util
  from tensorflow.python.ops import stateful_random_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
label_desc: Use image node_id 9 for calling the StatefulRandomOpsTest obj's underlying member method code with example usage: obj.testFnVars() and returns: rng