code: def testParallelVarianceForOneGroup(self):
      x = tf.constant(np.random.randn(5, 10))
      n = 5
      avg, var = tf.nn.moments(x, axes=[0])
      m2 = var * n
      (
          new_n,
          new_avg,
          new_m2,
          _,
      ) = tensor_normalizer.parallel_variance_calculation(
          n, avg, m2, n_b=0, avg_b=0, m2_b=0, m2_b_c=0
      )
      new_var = new_m2 / n
      (avg, var, new_avg, new_var) = self.evaluate(
          (avg, var, new_avg, new_var)
      )
      self.assertEqual(new_n, 5)
      self.assertAllClose(new_avg, avg)
      self.assertAllClose(new_var, var)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import functools
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tf_agents.specs import tensor_spec
  from tf_agents.utils import tensor_normalizer
label_desc: Use image node_id 2 for calling the ParallelVarianceTest obj's underlying member method code with example usage: obj.testParallelVarianceForOneGroup() without return types