code: def forward_chainerx(self, inputs):
      x, gamma, beta = inputs
  
      running_mean = chainerx.array(self.running_mean, copy=True)
      running_var = chainerx.array(self.running_var, copy=True)
  
      y = chainerx.batch_norm(
          x,
          gamma,
          beta,
          running_mean=running_mean,
          running_var=running_var,
          **self.optional_args,
      )
  
      # Record running values for later checks.
      self.running_mean_chx = running_mean
      self.running_var_chx = running_var
  
      return (y,)
  
imports: import unittest
  import chainer
  import numpy
  import pytest
  import chainerx
  import chainerx.testing
  from chainerx_tests import array_utils
  from chainerx_tests import op_utils
label_desc: Use image node_id 3 for calling the TestBatchNorm obj's underlying member method code with example usage: obj.forward_chainerx(inputs) and returns: y