code: def check_forward(self, x_data):
      y = self.link(x_data)
      self.assertEqual(y.data.dtype, self.dtype)
  
      unbatched_concat_y = chainer.functions.concat(
          [self.link(one_x[None,]) for one_x in x_data], axis=0
      )
  
      testing.assert_allclose(
          y.data, unbatched_concat_y.data, **self.check_forward_optionss
      )
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import gradient_check
  from chainer import links
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import condition
  from chainer.utils import type_check
label_desc: Use image node_id 2 for calling the LayerNormalizationTest obj's underlying member method code with example usage: obj.check_forward(x_data) without return types