code: def test_valid_batch_no_batch_axis(self):
      args = self.create_batch(
          (
              1,
              3,
          ),
          (1, 3, 2),
      )
      with warnings.catch_warnings(record=True) as w:
          functions.batch_normalization(*args, axis=2)
          assert len(w) == 0
  
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 6 for calling the TestBatchNormalizationWarning obj's underlying member method code with example usage: obj.test_valid_batch_no_batch_axis() without return types