code: def forward_cpu(self, inputs, running_mean, running_var):
      y_expect = _batch_normalization(
          inputs + [self.mean, self.var, self.eps, self.expander],
          running_mean,
          running_var,
          self.decay,
      )
      return (y_expect,)
  
imports: import unittest
  import warnings
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import backend
label_desc: Use image node_id 2 for calling the TestBatchNormalization obj's underlying member method code with example usage: obj.forward_cpu(inputs, running_mean, running_var) and returns: y_expect