code: def test_valid(self):
      functions.batch_normalization(*self.args, eps=1e-5)
  
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 TestBatchNormalizationCudnnEps obj's underlying member method code with example usage: obj.test_valid() without return types